Assessing prescription writing skills of pre-clerkship medical students in a problem-based learning curriculum

OBJECTIVE

To audit the acquisition of prescribing skills of pre-clerkship medical students in a problem-based learning (PBL) curriculum that incorporates a prescribing program.

MATERIAL AND METHODS

Student performance in pharmacotherapy stations included in six out of eight end-of-unit-objective structured practical examinations (OSPE) was evaluated using a rating checklist.

RESULTS

Prescription writing skills of 539 students (66.2% female and 33.8% male) were appraised. With the exception of refill element, the other physician-related components including prescriber's identity, date of prescription order, patient's identity, the symbol Rx "Take Thou", and prescriber's signature were written by 96.1% of the students (95% confidence interval (CI) 94.1 - 97.5). However, the drug-related components such as the appropriateness of drug(s) selected, strength, dosage form, quantity to be dispensed and directions for use were written satisfactorily by 50.2% of the students (95% CI 46.0 - 54.4). With respect to prescribing skills, the mean total score of Year 4 students did not significantly differ from that of Year 2 (69.4 (CI 65.7 - 73.1) vs. 66.3 (CI 62.7 to 69.9); p = 0.237). However, the mean scores of individual drug-related components such as appropriateness of drug(s) selected, dosage form, and direction for use were significantly higher in Year 4 than that of Year 2 students (p < 0.05). Of 381 rationally prescribed drugs, 81.1% were written with generic names.

CONCLUSION

This study revealed that the students acquire prescribing skills to a limited extent during the pre-clerkship phase in a PBL program. Prescribing errors and deficits were found to be mainly associated with drug-related components. Further training and assessment of prescribing skills during the clerkship and internship period are needed to achieve mastery of this skill as a terminal competency of graduating physicians.

Antihypertensive drug-associated sexual dysfunction: a prescription analysis-based study

PURPOSE

To determine whether primary care physicians take into consideration age, gender and diabetes mellitus as risk factors for sexual dysfunction (SD) when prescribing antihypertensives.

METHODS

A prescribing survey on hyperternsive patients with or without diabetes mellitus in primary care setting of Bahrain was carried out.

RESULTS

In 5301 hypertensive patients, we found that a beta-blocker (atenolol) was the most commonly prescribed drug and was significantly more often prescribed for young male hypertensives (< 45 years). A relatively high dose of atenolol (100 mg/d) was extensively used as both mono- and combination-therapies. With the exception of middle-aged hypertensives (45-64 years) and elderly diabetic-hypertensives (> or = 65 years), no significant age- and gender-related differences were observed regarding the prescription of thiazide diuretics. A significant trend of prescribing methyldopa in females as monotherapy was evident. Angiotensin converting enzyme (ACE) inhibitors, the second most commonly prescribed drugs, were significantly more often prescribed for young, middle-aged hypertensive males and for middle-aged diabetic-hypertensive males. beta-blocker/diuretic combination was prescribed least for the young and elderly hypertensive males. However, prescription of an ACE inhibitor with either a diuretic or a calcium channel blocker (CCBs) was less frequent and lacked gender-related differences.

CONCLUSIONS

We infer that antihypertensive-induced SD received little attention as was evident from: (a) over-prescription of relatively high dose of beta-blockers to young hypertensive males; (b) lack of gender- and age-related difference regarding the type and dose of diuretics prescribed; (c) underutilization of effective and complementary combinations expected to cause least impact on sexual function, such as ACE inhibitors with either a diuretic or with a CCB; and (d) a relative lack of discrimination while selecting antihypertensive drugs, particularly as monotherapy between hypertensive versus diabetic-hypertensive patients. With the exception of ACE inhibitors alone and combination of diuretic/beta-blocker, the choice of antihypertensives did not conform to international guidelines. In view of drug-induced SD adversely influencing the quality of life and thereby drug-compliance, interventions aimed at improving physicians' awareness should be attempted.

Design and rationale of CONTRAST--a prospective, randomized, placebo-controlled trial of fenoldopam mesylate for the prevention of radiocontrast nephropathy

Radiocontrast-induced nephropathy develops in approximately 10% to 20% of patients following administration of iodine-based dye and is one of the most prognostically detrimental complications that invasive cardiologists and radiologists encounter. Preexisting renal dysfunction and diabetes mellitus are two of the most powerful predictors of the likelihood of developing acute renal insufficiency after contrast delivery. To date, only adequate preprocedural hydration and postprocedural hydration to offset dehydration from contrast-induced diuresis have been shown to be effective in preventing this condition. Fenoldopam mesylate, a systemic vasodilator currently FDA-approved for short-term, in-hospital management of severe hypertension, has been shown to increase renal plasma flow in patients with and without chronic renal insufficiency. As a selective agonist of the dopamine-1 receptor, fenoldopam may preserve outer medullary renal blood flow and thereby attenuate radiocontrast-induced nephropathy. Small studies with fenoldopam prior to iodine-based dye administration have demonstrated low rates of radiocontrast nephropathy, and a larger, randomized trial has found that renal blood flow 1 hour after angiography rose in the fenoldopam group compared to a decline in the placebo group. The CONTRAST study has been designed to determine whether fenoldopam is indeed effective in diminishing the occurrence of radiocontrast-induced nephropathy.

Pathophysiology of radiocontrast nephropathy and use of fenoldopam for its prevention

There are no proven therapeutic agents for the prevention or treatment of acute renal failure. Radiocontrast agents induce intense vasoconstriction in the renal medulla, which is hypoxic even in normal physiologic states, thereby aggravating the imbalance of medullary oxygen supply and demand. Fenoldopam specifically increases blood flow to the renal medulla through selective agonism of dopamine-1 receptors and has been found to prevent radiocontrast nephropathy in several investigations, including one randomized, double-blind, placebo-controlled trial.

Trends in ophthalmic antimicrobial utilization pattern in Bahrain between 1993 and 2000: a resurgence of chloramphenicol?

OBJECTIVES

The occurrence of aplastic anemia following topical administration of ophthalmic chloramphenicol is controversial and debated internationally. We have determined the influence of such debate on the utilization of ophthalmic chloramphenicol in Bahrain, through studying the utilization patterns of ophthalmic antimicrobial preparations by the Ministry of Health, with an emphasis on chloramphenicol, between 1993 and 2000. Cost-implications of these patterns are examined.

MATERIAL AND METHODS

Information on the annual purchase of ophthalmic antimicrobial drug preparations and their unit price was obtained from the Directorate of Materials Management, Ministry of Health, and analyzed.

RESULTS

In 1993, the 3 most commonly purchased ophthalmic antibacterial preparations were oxytetracycline 1% eye ointment (40.1%); sulfacetamide 10% and 20% eye drops (25.3%); and chloramphenicol 0.5% eye drops and 1% eye ointment (10.8%). In 2000, oxytetracycline remained the most frequently purchased preparation (33%), followed by chloramphenicol (21.2%). Between 1993 and 1999, chloramphenicol purchases fluctuated between 10% to 16.4% with a remarkable increase to 21.2%, in 2000. Chloramphenicol accounted for 8.6% and 15.1% of cost of total ophthalmic preparations purchased in 1993 and 2000, respectively.

CONCLUSION

Despite continued concerns of potential risks of ophthalmic chloramphenicol, this preparation is extensively utilized in Bahrain. We are of the opinion that for minor infections, chloramphenicol ophthalmic preparations should be replaced by safer alternatives. Further, we recommend that their use be reserved for ocular infections that are resistant to other antimicrobials, and that ophthalmologists, at the secondary care level, should supervise such treatment.

Extent of use of immediate-release formulations of calcium channel blockers as antihypertensive monotherapy by primary care physicians: multicentric study from Bahrain

BACKGROUND

The issue of cardiovascular safety of calcium channel blockers (CCBs) has been widely debated in view of reflex increase in sympathetic activity induced by immediate release (IR) / short acting formulations. It is generally agreed that such CCBs should not be used alone in the management of hypertension.

AIMS

We have determined the extent to which primary care physicians prescribe CCBs as monotherapy, especially the immediate release formulations, in the management of uncomplicated hypertension and diabetic hypertension - with an emphasis upon the age of the patients. SETTING, DESIGN AND METHODS: A retrospective prescription-based study was carried out in seven out of 18 Health Centres in Bahrain. The study involved a registered population of 229,300 representing 46% of registered individuals, and 35 physicians representing 43% of all primary care physicians. The data was collected between November 1998 and January 1999 using chronic dispensing cards.

RESULTS

In all categories CCBs were the third commonly prescribed antihypertensive as monotherapy, with a prescription rate of 11.1% in uncomplicated hypertension, 18% in diabetic hypertension and 20.1% in elderly patients above 65 years of age. Nifedipine formulations were the most extensively prescribed CCBs. Almost half of the CCB-treated patients were on IR-nifedipine, whereas IR-diltiazem and IR-verapamil, and amlodipine were infrequently prescribed.

CONCLUSION

Prescription of IR-formulations of CCBs as monotherapy by primary care physicians does not conform with recommended guidelines. In view of concerns about the safety of such practice, measures to change the prescribing pattern are required.

Fenoldopam mesylate blocks reductions in renal plasma flow after radiocontrast dye infusion: a pilot trial in the prevention of contrast nephropathy

BACKGROUND

Radiocontrast nephropathy (RCN) is a common source of acute renal failure in hospitalized patients and is associated with increased morbidity and mortality rates. Fenoldopam mesylate is a dopamine A1 receptor agonist that augments renal plasma flow (RPF) in patients with normotensive and hypertensive conditions. To determine whether fenoldopam mesylate attenuates reductions in RPF after contrast infusion, we conducted a double-blind, randomized, placebo-controlled pilot trial of fenoldopam mesylate in patients who underwent contrast angiography.

METHODS

Fifty-one patients with chronic renal insufficiency (creatinine level, 2.0-5.0 mg/dL) who were undergoing contrast angiography were screened, and 45 patients were randomized to receive normal saline solution (1/2 NS) or 1/2 NS plus fenoldopam mesylate at 0.1 microg/kg/min at lease 1 hour before infusion with contrast dye. Serum creatinine level was measured at baseline and at 24, 48, and 72 hours after angiography. The primary endpoint was change in RPF 1 hour after contrast infusion. The secondary endpoint was incidence of RCN, defined as a 0.5 mg/dL or a 25% rise in serum creatinine level at 48 hours.

RESULTS

RPF at 1 hour after angiography was 15.8% above baseline in the fenoldopam mesylate group compared with 33.2% below baseline in the 1/2 NS group (P <.05). The incidence rate of RCN at 48 hours was 41.0% in the 1/2 NS group versus 21% in the fenoldopam mesylate group (P =.148). Among patients with diabetes, the incidence rate of RCN tended to be higher in the 1/2 NS group compared with the fenoldopam mesylate group (64% vs 33%; P =.14). The peak serum creatinine level at 72 hours after contrast infusion was significantly higher at in the 1/2 NS group (creatinine level, 3.6 +/- 1.0 mg/dL) compared with the fenoldopam mesylate group (creatinine level, 2.8 +/- 0.35 mg/dL; P <.05). RPF was significantly (P <.0001) reduced in patients with RCN compared with patients in whom RCN did not develop.

CONCLUSION

The results of this pilot trial suggest that fenoldopam mesylate is a promising prophylactic agent for RCN and that larger multicenter trials should be conducted to prove its efficacy.

Prescribing patterns and therapeutic implications for diabetic hypertension in Bahrain

OBJECTIVE

To determine drug prescription patterns and the extent of conformity with World Health Organization/international Society of Hypertension (WHO/ISH) guidelines in diabetic hypertension.

DESIGN

Retrospective prescription-based survey.

SETTING

Seven primary-care health centers, comprising approximately one-third of primary-care health centers in Bahrain.

PATIENTS

Patients with type 2 diabetes and hypertension.

MAIN OUTCOME MEASURE

The prescribing pattern of antihypertensive and antidiabetic drugs.

RESULTS

Among a study sample of 1,463 patients with type 2 diabetes and hypertension, antidiabetic agents were prescribed as monotherapy in the following descending order: glyburide, gliclazide, insulin, and metformin. As combinations, sulfonylureas plus metformin was most popular, followed by metformin plus insulin, and sulfonylureas plus insulin. Sulfonylurea and metformin with insulin was rarely used. There was no significant difference in prescribing of glyburide and metformin between the elderly and young middle-aged diabetic patients; many patients older than 65 years were treated with a beta-blocker along with a long-acting sulfonylurea. Both as monotherapy and in overall use, beta-blockers, angiotensin-converting enzyme (ACE) inhibitors, and calcium-channel blockers were most often prescribed. Among 35.5% patients treated with antihypertensive combinations, various two- and three-drug combinations of beta-blockers, ACE inhibitors, calcium-channel blockers, and diuretics were often used. The proportion of patients taking atenolol 100 mg/d was higher with combination regimens. Hydrochlorothiazide 25 mg or equivalent thiazide diuretics were extensively used.

CONCLUSIONS

The prescribing pattern of antihypertensives in diabetic hypertension differs in many instances from WHO/ISH guidelines, especially regarding the choice of antihypertensive drugs and their combinations. The appropriateness of antidiabetic drug choice is questionable in relation to the antihypertensive used.

Antihypertensive drug prescription trends at the primary health care centres in Bahrain

PURPOSE

To determine the antihypertensive drug prescribing pattern by primary care physicians in patients with uncomplicated essential hypertension; to identify whether such pattern of prescription is appropriate and in accordance with international guidelines for pharmacotherapy of hypertension; and to estimate the impact of such prescriptions on cost of treatment.

METHODS

A prescription-based survey among patients with uncomplicated essential hypertension was conducted in seven out of a total of 18 health centres in Bahrain. The relevant data for our study was collected using cards, designed for chronically-ill patients.

RESULTS

A total of 1019 male and 1395 female (62.9%) out of 3838 of the study population were on monotherapy, whereas 596 male and 828 female (37.1%) were on antihypertensive combination therapy. Among the monotherapy category, the various antihypertensive drugs used were as follows: beta-blockers (58.8%), angiotensin converting enzyme (ACE) inhibitors (14.2%), calcium channel blockers (11.1%), diuretics (8.1%) and alpha-methyldopa (7.0%). With respect to overall utilization pattern, beta-blockers were the most frequently prescribed (65.5%), diuretics ranked second (27.4%), followed by ACE inhibitors (20.6%), calcium channel blockers (19.9%) and alpha-methyldopa (8.5%). Within each class of antihypertensives used, the most frequently used individual agents were as follows: (a) among beta-blockers 97.7% used atenolol; (b) among the diuretics, indapamide (35.4%), hydrochlorothiazide (HCTZ) (32.7%), HCTZ in combination with triamterene (25.7%), and chlorthalidone (4.6%); (c) among the ACE inhibitors, captopril (44.9%), enalapril (29.7%), and lisinopril (19.0%); (d) among the calcium channel blockers, nifedipine (98.2%). Significant age- and gender-related differences in prescribing patterns were seen. Short-acting nifedipine monotherapy was inappropriately prescribed in a significant number of patients above the age of 50 years. ACE inhibitors accounted for approximately two-thirds of the total antihypertensive drug expenditure, although these drugs represent only one-fifth of overall antihypertensives used. There is a trend towards excessive use of expensive thiazide-like diuretics such as indapamide which seems to be unjustifiable practice, particularly in a study population free from diabetic hypertensive patients.

CONCLUSIONS

The general pattern of antihypertensive utilization appears to be in accordance with the guidelines of WHO and the Joint National Committee issued in the 1990s. The trends of prescribing of antihypertensives were in favour of conventional ones such as the beta blockers and diuretics, and the introduction of newer classes of antihypertensives had a generally minimal impact on the prescribing profile. Almost two-thirds of the patients were treated with monotherapy. A disproportionately large percentage of antihypertensive drug cost was due to overt use of ACE inhibitors, and indapamide, instead of thiazide diuretics. The use of short-acting calcium channel blockers especially in the elderly is unjustifiable.

Rational pharmacotherapy of hypertension in the elderly: analysis of the choice and dosage of drugs

OBJECTIVES

To determine in older people with uncomplicated hypertension: (a) the pattern of prescribing of antihypertensives; (b) the extent of physicians' adherence to recommendations on dosage for antihypertensive combinations; (c) whether prescribing practice conforms with recommended therapeutic guidelines; and (d) the frequency of prescribing of other drugs which have the potential to alter the efficacy of antihypertensive agents.

METHODS

A survey of prescribing in older patients with uncomplicated hypertension in primary care setting of Bahrain was conducted.

RESULTS

Of the 432 (56.5%) patients on monotherapy, 192 (44.4%) were treated with beta-blockers, 87 (20.1%) with calcium channel blockers (CCBs), 53 (12.3%) with alpha-methyldopa, 47 (10.9%) with diuretics, 46 (10.6%) with angiotensin converting enzyme (ACE) inhibitors, and 7 (1.6%) with hydralazine. Of the 1146 patients on mono- or combination therapies, 434 (56.8%) were treated with beta-blockers, 244 (31.9%) with diuretics, 211 (27.6%) with CCBs, 139 (18.2%) with ACE inhibitors, 103 (13.5%) with alpha-methyldopa 8 (1.0%) with brinerdine and 7 (0.9%) with hydralazine. In the 332 (43.5%) patients on combination therapy, 15 different two- and three-antihypertensive drug combinations were prescribed: a diuretic with a beta-blocker (37.2%) and a beta-blocker with either a CCB (20.9%) or an ACE inhibitor (12.4%) were the most popular two-drug regimens. The most commonly prescribed triple drug regimens were a diuretic and a beta-blocker plus either a CCB (26.1%) or an ACE inhibitor (17.4%) and diuretic plus an ACE inhibitor and a CCB (15.2%). Daily dosage of beta-blockers, ACE inhibitors and alpha-methyldopa were somewhat high in a considerable proportion of patients on both mono- and combined therapies. A substantial proportion (9.7%) of patients on monotherapy were treated with immediate release nifedipine.

CONCLUSION

The pharmacotherapy of hypertension in elderly patients was found in some instances not to conform to recommended guidelines. For certain classes of antihypertensive agent such as beta-blockers, ACE inhibitors and alpha-methyldopa, neither the principles of geriatric pharmacology nor of antihypertensive combination therapy, and in particular, the need to reduce daily dosage, were followed. The use of immediate release nifedipine in the elderly is irrational, and instead, the use of long-acting dihydropyridine CCBs should be considered. The results of long-term randomized clinical trials published during the last decade have had a minimal impact on clinical practice of primary care physicians in Bahrain.

Recruitable patency of the internal mammary artery graft

A 46-year-old man underwent two coronary bypass operations and three percutaneous interventions over a period of 18 years. A non-functioning internal mammary artery (IMA) graft, was observed shortly after the second surgery. This graft was anastomosed to the left anterior descending (LAD) that had adequate flow from an older vein graft placed during the first surgery. Over the ensuing 8 years, the IMA graft regained patency after progressive occlusive disease in the competing vein graft.

Patterns of utilization of antihypertensive drug combinations in Bahrain: do they conform with international guidelines?

OBJECTIVES

To explore the prescribing pattern and rationale of antihypertensive combination drug therapy at the level of primary health care centers; and to analyze the extent of physicians' adherence to dosage range of antihypertensives in combination regimens as recommended by Guidelines Subcommittee of WHO/ISH 1999.

SUBJECTS, MATERIAL AND METHODS

A prescribing survey of antihypertensive combination regimens among patients with uncomplicated essential hypertension was conducted in 7 out of a total of 18 health centers in Bahrain. The relevant data for our study was collected using cards designed for chronically ill patients.

RESULTS

A total of 2414 hypertensive patients (62.9%), of a 3838 study population, were on monotherapy, whereas 1414 (37.1%) were on antihypertensive combination therapy. Among those who were treated with drug combinations, 85.1% (n = 1212) received two-drug, 14.2% (n = 202) received three-drug and four- and five-drug regimens were used by 0.6% and 0.07%, respectively. Prescription analysis revealed that 17 different two- and three-antihypertensive drug combinations were prescribed for each category. The four major two-drug regimens were ranked in the following order: a beta-blocker with a diuretic (40.4%) used more frequently in females than in males (p < 0.0001), a beta-blocker with a calcium channel blocker (19.7%), a beta-blocker with an ACE inhibitor (12.8%) and a diuretic with an ACE inhibitor (7.3%) - used more frequently in males than in females (p = 0.001, 0.01, and 0.028, respectively). The most frequently prescribed three-drug regimens were diuretic and a beta-blocker plus either an ACE inhibitor (30.7%) or a calcium channel blocker (22.3%), beta-blocker plus an ACE inhibitor and a calcium channel blocker (16.3%), and a diuretic plus an ACE inhibitor and a calcium channel blocker (11.4%). There was no gender-related difference among triple-drug regimens. There was a trend towards using high doses of the beta-blocker atenolol, ACE inhibitors and methyldopa.

CONCLUSION

The prescribing patterns of some practising physicians were analyzed in terms of conformity with guidelines of combination of drugs and dosages. The use of antihypertensive combination therapy and the doses of individual drugs in combination regimens seem to be partly non-compliant with guidelines issued by WHO recommendations; this is illustrated by excessive prescription of some irrational combinations, as well as limited prescription of some rational combinations. In addition, a tendency to use high doses of certain classes of antihypertensive combinations was observed.

The string phenomenon: an important cause of internal mammary artery graft failure

Internal mammary arteries are the grafts of choice for coronary artery bypass because they are generally free of atherosclerosis and they have high patency rates as grafts. There are, however, increasing reports of graft failure due to diffuse or distal narrowing, known as the string phenomenon. From June 1999 to October 1999, we prospectively reviewed all cases of internal mammary artery angiography at our institution. Twenty-eight cases of internal mammary artery graft failure were identified (M:F, 15:13; mean age, 62 years) out of 261 patients who had undergone internal mammary artery grafting at any institution, including ours. The mean interval between coronary artery bypass and re-angiography was 35 months. There was evidence of competitive flow in 81% (22 of 27) of patients whose internal mammary grafts had developed the string sign. This observational study supports the hypothesis that competitive flow predisposes internal mammary grafts to the string phenomenon. Given the high frequency of competitive flow situations amongst patients with internal mammary artery graft failure, caution should be exercised in the anastomosis of the internal mammary artery to recipient vessels that are less than severely stenosed.

The effects of fenoldopam, a selective dopamine receptor agonist, on systemic and renal hemodynamics in normotensive subjects

OBJECTIVE

Acute renal failure, frequently a consequence of renal vasoconstriction and subsequent renal ischemia, is a common problem for which no proven preventive or therapeutic agents exist. Fenoldopam is a new, selective, dopamine-1 receptor agonist that causes both systemic and renal arteriolar vasodilation. In hypertensive patients, fenoldopam rapidly decreases blood pressure, increases renal blood flow, and maintains or improves the glomerular filtration rate. We sought to determine a dose of fenoldopam that increases renal blood flow without inducing hypotension in normotensive patients and to explore the role of volume status (sodium replete vs. deplete) in these effects.

DESIGN

Randomized, double-blind, placebo-controlled, cross-over study.

SETTING

Clinical research unit.

PATIENTS

Fourteen normal male volunteers.

INTERVENTIONS

Renal plasma flow (para-aminohippurate clearance) and glomerular filtration rate (inulin clearance) were measured during three fixed, escalating doses of fenoldopam (0.03, 0.1, and 0.3 Lg/kg/min) on both a high-sodium and a low-sodium diet.

MEASUREMENTS AND MAIN RESULTS

Fenoldopam significantly increased renal plasma flow in a dose-dependent manner compared with placebo: 670 + 148 vs. 576 + 85 mUmin at 0.03 iLg/kg/min; 777 + 172 vs. 579 + 80 mUmin at 0.1 tig/kg/min; and 784 + 170 vs. 592 + 165 mUmin at 0.3 ilg/kg/min (p < .05 fenoldopam vs. placebo at all three doses). Glomerular filtration rate was maintained. At the lowest dose (i.e., 0.03 ILg/kg/min), significant renal blood flow increases occurred without changes in systemic blood pressure or heart rate. At 0.1 and 0.3 Lgl/kg/ min, systolic blood pressure did not change, but diastolic blood pressure was slightly lower in the fenoldopam group than in the placebo group: 62.5 + 6.4 vs. 63.6 + 2.6 mm Hg, respectively, at 0.3 tg/kg/min (p < .05). None of the effects of fenoldopam were altered by volume status.

CONCLUSIONS

Fenoldopam increased renal blood flow in a dose-dependent manner compared with placebo, and, at the lowest dose, significantly increased renal blood flow occurred without changes in systemic blood pressure or heart rate. These findings will be useful in designing future studies exploring the role of fenoldopam in preventing or treating renal failure in patients who are not hypertensive.

Acute renal allograft dysfunction secondary to suprarenal arterial stenosis: a case series and review of the literature

Stenosis of vessels proximal to the renal artery is an unusual cause of allograft ischemia. We report four patients who had such 'suprarenal' arterial stenoses leading to graft dysfunction that was reversed with revascularization. We additionally review the existing literature on this entity, outline the etiologies of such stenoses, as well as discuss the surgical and non-surgical therapeutic options in patients with this uncommon cause of allograft dysfunction.

Polyomavirus-induced interstitial nephritis in two renal transplant recipients: case reports and review of the literature

We present two case reports of renal polyomavirus infection leading to renal allograft dysfunction, review the literature of this entity, and discuss the role of specific immunosupressives. Histologically, the virus caused an interstitial infiltrate composed of plasma cells and lymphocytes, interstitial fibrosis, and tubular atrophy. Viral inclusions were seen within tubular cells on light microscopy. Electron microscopy showed viral particles of 40 to 50 nm in a characteristic paracrystalline array. Both patients had been on FK-506-based immunosuppression. In both patients, the virus appeared to clear histologically and renal function stabilized when the patients were converted to cyclosporine-based immunosuppression. Contrary to prior reports, our patients have not lost their grafts and continue to have stable, albeit reduced, graft function at 2.5 years and 4.5 years following the initial diagnosis of renal polyomavirus infection.

Low-molecular-weight heparin and abciximab for thrombo-occlusive saphenous vein graft disease. Report of 2 cases

Both reoperation and alternative treatments for thrombo-occlusive disease of saphenous vein grafts have been fraught with a high rate of complications and a low rate of long-term success. We report 2 cases in which thrombo-occlusive saphenous vein graft disease was treated with the aid of abciximab during the intervention and with low-molecular-weight heparin for 7 to 12 days in an outpatient setting.

Noninvasive assessment of left ventricular function in asymptomatic diabetics and its relation to metabolic control and microangiopathy

Fifty otherwise healthy patients with diabetes mellitus (37 males, 13 females; mean age: 53 +/- 10 years) of more than five year duration were compared with twenty six healthy age and sex matched controls. Detailed echocardiographic evaluation was done in all and systolic time intervals (STI) were measured. In diabetics, metabolic control and presence of microangiopathy were evaluated. PEP Index (patients: 146.23 +/- 17.04; controls: 121.99 +/- 5.15; p less than 0.001), PEP/LVET ratio (patients: 0.38 +/- 0.07; controls: 0.32 +/- 0.02; p less than 0.001), LVEF% (patients: 54.1 +/- 10.56; controls: 64.71 +/- 6.33; p less than 0.001), all were significantly altered in diabetics suggesting left ventricular dysfunction. The left ventricular posterior wall thickness (patients: 0.96 +/- 0.23 cm; controls: 0.85 +/- 0.12 cm; p less than 0.01) and interventricular septal thickness (patients: 1.2 +/- 0.24 cm; controls: 0.87 +/- 0.25 cm; p less than 0.001) in diastole were increased in diabetics. The PEPI correlated with day-to-day control but not with chronic glycemic control of diabetes mellitus. The PEP/LVET was significantly increased in patients with severe, as compared to those with none or mild microangiopathy (p less than 0.05). Thus, significant left ventricular dysfunction is evident in asymptomatic, otherwise healthy diabetics. Both metabolic control and microangiopathy may be responsible for the abnormalities.

Disposition of sulphadiazine in young rhesus monkeys with protein calorie malnutrition

Disposition of sulphadiazine was assessed in young rhesus monkeys under three stages of nutritional manipulations i.e. control, protein calorie malnutrition (PCM) state and following nutritional rehabilitation. There was no alteration in the absorption kinetics except a delayed peak in the malnourished group. A decrease in volume of distribution of drug in the peripheral compartment was noted. The most significant changes observed was in the elimination kinetic parameter. The (Ke) elimination rate constant and the clearance rate showed a significant decrease which could be either because of decreased rate of acetylation or a decrease volume of distribution.

A scoring system for selection of essential drugs

A scoring system is presented for selection of essential drugs, using criteria of efficacy, safety, cost of a course of therapy, compliance, multiple usage and storage, ease of administration and local availability. Such a system allows for different weighting of factors whose relative importance varies from country to country and would help in choosing the most appropriate and cost-effective drugs for use in developing countries. The importance of such factors as cost and compliance has been illustrated with suitable examples. This approach could also be used for individual patient decisions with the aid of a computer program.

Coronary artery anomalies: a review of more than 10,000 patients from the Clayton Cardiovascular Laboratories

We reviewed the records of 10,661 patients who had undergone coronary angiography at the Clayton Foundation Cardiovascular Laboratories between 1 June 1974 and 15 March 1986, and identified major coronary artery anomalies in 83 adults. In addition, we included in our review 9 adults and 2 adolescents who had been referred for evaluation of anomalies documented elsewhere. Here we present the clinical and angiographic data for all 94 patients (76 men and 18 women). Most patients were men who presented with chest pain. The most common anomaly, found in 38 patients, was origin of left circumflex coronary artery from right coronary artery or right aortic sinus. In contrast to other studies, which have not shown increased incidence of coronary atherosclerosis in the anomalous circumflex artery, 71% of our patients with this anomaly had significant coronary atherosclerosis in the proximal portion of the anomalous vessel. The posterior course of the anomalous circumflex coronary artery may predispose this vessel to atherosclerosis in patients with coronary disease. The overall incidence of atherosclerotic disease in coronary arteries was 68% (64 of 94 patients) in the present study.

Comparative bioequivalence study of furosemide in patients with edema of renal origin

A double-blind cross-over randomized clinical study with two different brands of furosemide was carried out in seven patients with edema of renal origin. The study indicated that the two brands were biologically equivalent.

Effect of tolbutamide treatment on the pharmacokinetics of intravenously administered sulphamethoxazole in rabbits

Fifteen days of tolbutamide treatment significantly decreased the elimination half life (t1/2), area under the curve (AUC0----infinity) and increased the clearance of sulphamethoxazole (SMZ) in rabbits. No significant difference was observed in the volume of distribution. The percentage of plasma protein binding to SMZ was not altered, while N-acetyltransferase activity in liver and kidney was significantly increased after tolbutamide therapy. The changes observed in the pharmacokinetic parameters of SMZ after tolbutamide treatment is due to the induction of liver N-acetyltransferase activity.

Effect of Rumex nepalensis extracts on histamine, acetylcholine, carbachol, bradykinin, and PGs evoked skin reactions in rabbits

The antihistaminic, anticholinergic, antibradykinin, and/or antiprostaglandin activity of aqueous and the alcoholic leaf extracts of the plant Rumex nepalensis were tested on the prepared site on the back of rabbits, using a control and a test site. Aqueous extract was found to reduce the mean size of the wheal produced by histamine, acetylcholine, carbachol, and bradykinin. The alcoholic extract reduced the size of the wheal produced by histamine, acetylcholine and carbachol. The results indicate that Rumex nepalensis may have antihistaminic, anticholinergic, and/or antibradykinin activity.

Assessment of bio(in)equivalence of deriphyllin-digoxin in human volunteers

Bioavailability of digoxin from the formulations of a fixed dose combination of the glycoside with xanthines was compared with that of "Lanoxin". The in vitro analysis of the fixed dose "Deriphyllin-Digoxin" tablets showed that these tablets had low dissolution even at the end of four hours. The in vivo study had a randomized cross-over design with a 14 days wash-out period. The formulations were administered to 14 healthy adult volunteers and periodic blood samples were collected up to 24 hours. The samples were analyzed for digoxin concentration using radioimmunoassay. Results indicate poor and delayed absorption of digoxin from the fixed dose combination. It is concluded that a multiple dose study with pharmacodynamic assessment, in patients or in volunteers, would be adequate to critically reassess the need for the marketed fixed dose combination.

Comparative pharmacokinetic study of four different sulfonamides in combination with trimethoprim in human volunteers

The pharmacokinetics of four different sulfonamides i. e., sulfamethoxazole (SMZ). Sulfamoxole (SMO), Sulfadiazine (SDZ) and Sulfadimidine (SDD) in combination with trimethoprim (TMP) were studied in 12 healthy volunteers. Plasma and urine concentrations of sulfonamides were measured at different time intervals. No significant difference was observed in the area under the plasma curve (AUC) of SMZ, SMO and SDZ, while AUC of SMO was significantly higher than SDD only. Free (unmetabolized) SDZ urinary excretion during a 10-25 h period was significantly higher than SMZ, SMO and SDD. The results suggest that SDZ alone or in combination with TMP would be more effective in urinary tract infections as compared to other sulfonamides studied.

GABAergic, dopaminergic and cholinergic interactions in perphenazine-induced catatonia in rats

Anticatatonic effects of systemic and intracerebroventricularly administered GABAergic agents (GABA, muscimol piracetam, sod. valproate) were studied in rats against perphenazine-induced catatonia. All GABAergic agents, except piracetam, were found to posses anticatatonic actions as they significantly blocked perphenazine-induced catatonia. When these GABAergic agents were administered simultaneously with anticholinergic (scopolamine) or dopaminergic (bromocriptine) substances there was potentiation of the anticatatonic effect. The protective effect of GABAergic agonists and GABA antagonist and its modification by anticholinergic and dopaminergic agents has been explained on the basis of neurotransmitter interaction.

Myocardial infarction associated with cocaine abuse

We report a patient who sustained a myocardial infarction after inhaling cocaine. He developed a persistent wall motion defect that was present 18 months after the acute event despite resolution of electrocardiographic evidence of infarction.

Disposition of acetaminophen in children with protein calorie malnutrition

Acetaminophen disposition was studied in 11 children suffering from Protein Calorie Malnutrition (PCM) and 5 (age matched) control subjects using the time plasma concentration curve obtained after a single oral administration of 10 mg/kg of the drug. Absorption rate constant (Ka) was not altered in PCM. Elimination rate constant (Ke) was decreased significantly. PCM children had Ke 0.108 +/- 0.015 h-1 in comparison to the control value of 0.170 +/- 0.022 h-1. Plasma half-life (t1/2) was increased in PCM (8.14 +/- 1.30 h) in comparison of the control (4.33 +/- 0.52 h). Area under the curve (AUC) was also significantly increased in PCM (88.88 +/- 21.36 ug h/ml/kg) compared to the control (25.05 +/- 2.99 ug h/ml/kg). Time of drug disappearance was 44.7 +/- 7.1 hours in PCM compared to 24.6 +/- 3.3 hours in the control. Five PCM subjects could be restudied after rehabilitation and they demonstrated the return of elimination parameters towards control values. Drug therapy needs revision in light of these findings.

Impairment of drug elimination in patients with liver disease

An attempt has been made to investigate drug elimination in patients with liver disease. Antipyrine was chosen as a model drug. The patients were divided into three groups depending upon clinical, biochemical, radiologic and histologic findings; (1) mild (Idiopathic portal hypertension, extrahepatic portal vein obstruction and Gilbert's syndrome); (2) moderate (Budd-Chiari syndrome and amoebic liver abscess); (3) severe (acute hepatitis, chronic active hepatitis and cirrhosis). A prolongation in antipyrine half-life (t1/2) was observed in 108 patients with liver disease (24.59 +/- 1.72 h) as compared to 12 controls (11.63 +/- 0.86 h). Similarly, metabolic clearance rate was decreased in all liver disorders. Among liver function tests, antipyrine t1/2 showed a significant correlation with serum albumin and prothrombin time index. After phenobarbitone administration, antipyrine clearance studied in 37 patients showed a significant decrease in t1/2 and an increase in MCR. Antipyrine t1/2 in 26 patients after recovery was comparable to those of controls.

Collateral circulation in coronary artery disease

The coronary arteriograms and left ventriculograms of 202 consecutive patients were reviewed. All had at least 75% diameter reduction of 1 or more major coronary arteries. In 127 patients (63%), at least 1 major branch was totally occluded. Collateral circulation was seen in 125 of these 127 patients (190 of 192 totally occluded arteries). Of the 75 patients without total occlusion, only 2 with 99% (or near-total) occlusion had demonstrable collateral circulation (2 of 208 arteries). In no patient with 75 to 98% diameter narrowing was collateral circulation demonstrated (0 of 164 arteries). An analysis was made of the relation between left ventricular (LV) segmental wall motion and the quality of collateral circulation in 190 totally occluded arteries among 125 patients. Of 126 arteries with good collateral circulation, LV contraction was normal in 21%, hypokinetic in 48% and akinetic/dyskinetic in 29%. Of 64 arteries with poor collateral circulation, LV contraction was normal in 23%, hypokinetic in 55% and akinetic/dyskinetic in 20%. There was no statistically significant difference between the effect of good or poor collateral circulation on LV function. These data indicate that collateral circulation cannot be seen angiographically unless there is total or near-total occlusion, and that the presence of collateral circulation does not correlate with LV wall motion abnormalities, i.e., akinetic area, despite good collateral flow or normal wall motion despite absent or poor collateral flow.

Restenosis after transluminal coronary angioplasty detected with exercise-gated radionuclide ventriculography

Forty-one patients were evaluated with exercise-gated radionuclide ventriculography before and within 4 days after successful transluminal coronary angioplasty and 4 to 12 months later. Patients were subgrouped according to the degree of restenosis demonstrated angiographically at 4 to 12 months (Group I [n = 23]: less than or equal to 20%; Group II [n = 10]: greater than 20% but less than 50%; Group III [n = 8]: greater than or equal to 50%). Patients with abnormal findings on gated radionuclide ventriculography (less than 5 point increase in ejection fraction or wall motion deterioration) early after angioplasty were eventually found to have a greater degree of restenosis than were patients with normal findings (41.2 +/- 30.3 versus 19.0 +/- 25.4% restenosis, p less than 0.0001). The accuracy of abnormal radionuclide ventriculography in predicting 50% or greater restenosis was 73% immediately after angioplasty and 77% at the time of follow-up angiography. Gated radionuclide ventriculographic results were abnormal in 5% of Group I patients compared with 75% of Group III patients (p less than 0.01) early after angioplasty; at late follow-up, they were abnormal in 27% of Group I patients compared with 88% of Group III patients (p less than 0.01). Group I patients had a greater increase in ejection fraction than did Group III patients at early (+11.3 +/- 7.5 versus + 3.5 +/- 6.5 points, p less than 0.01) and late (+11.8 +/- 7.8 versus -1.9 +/- 8.7 points, p less than 0.0005) follow-up. It is concluded that gated radionuclide ventriculography is useful in predicting coronary restenosis after transluminal coronary angioplasty.

Comparative bioequivalence study of furosemide in human volunteers

A double-blind cross-over randomized clinical study with two different brands of furosemide was carried out in sixteen normal volunteers. The study indicated that the two brands were biologically equivalent.

Coronary artery bypass for unsuccessful percutaneous transluminal coronary angioplasty

Of 518 consecutive patients undergoing percutaneous transluminal coronary angioplasty for 571 coronary lesions, 184 eventually underwent coronary artery bypass because of angioplasty failure. Delayed coronary bypass (1 week to 19 months) was done in 27 patients with no deaths. Immediate bypass was done in 87 patients with two deaths, both of which were caused by further dissection of the artery after angioplasty. Urgent bypass was required in 63 patients who were in unstable condition because of ischemia on the electrocardiogram (52 patients), unrelieved angina (57 patients), or hypotension (13 patients). There was one death in this group. In the remaining seven patients, urgent coronary bypass was done because of cardiac arrest (three deaths). Myocardial complications occurred in 23 of the 70 unstable patients, including the seven patients with cardiac arrest. There were only eight completed myocardial infarctions in the 70 unstable patients and a completed myocardial infarction rate of 11 of 184 (6.0%) overall. In the 10 patients in whom extracorporeal circulation was established within 25 minutes of myocardial insult, mortality and myocardial complications were completely avoided. The remaining patients in the urgent group were placed on cardiopulmonary bypass within 26 to 300 minutes (mean 82 minutes). Operative mortality (3.3%), completed myocardial infarction (6.0%), myocardial infarction in unstable patients (32.9%), postoperative hemorrhage (5.0%), and sternal problems (2.8%) were all significantly different from those in 3,500 consecutive coronary bypasses not following angioplasty, that were done in 1982.

Brand versus generic prescribing: a perspective of the Indian cardiologists' viewpoint

Pretested mail survey questionnaires consisting of four close-ended, six open-ended questions and an "anonymous prescribing" exercise were sent to 612 members of the Cardiological Society of India. This was done to assess their opinion regarding generic prescribing, to record the incidence of generic prescribing for digoxin and furosemide and to evaluate the extent of comprehension of novel terminology like bioequivalence, generic equivalence and therapeutic equivalence. The majority of the responders opted for brand prescribing and mentioned that substitution by a pharmacist was not acceptable. The reputation of the firm, availability and ease of remembering the name, cost and impact of medical representative were, in descending order, the reasons for the option of a specific brand name. The innovator's brand of digoxin (Lanoxin) was prescribed by 59% while 37% wrote the generic name. Lasix was the most often prescribed (77%) brand of furosemide. Comprehension of the novel terms was not related to years of practice or to the place of practice. The need for evaluation of brands encountered by the prescriber in future studies on brand versus generic prescribing has been emphasized.