The effect of indoramin on peripheral blood flow

1 The effect of indoramin, a new hypotensive agent, on peripheral blood flows of six normal subjects was determined and compared to placebo in a double-blind, randomized study. 2 Indoramin (0.25 mg/kg), administered intravenously, resulted in an increased forearm muscle volume as measured by strain gauge plethysmography and an increase in the skin temperature of the hand but not to the skin of the chest. 3 It is concluded that these effects are the result of α-adrenoceptor blockade.

Low-output syndrome after heart surgery: is a monotherapy with phosphodiesterase-III inhibitors feasible? A comparative study of amrinone and enoximone

In order to determine whether the primary use of a phosphodiesterase-III (PDE) inhibitor as monotherapy for severe cardiac low-output states (LOS) is in fact practicable, we investigated the haemodynamic effects of amrinone and enoximone in a prospective randomized study. After elective CABG, AVR, or MVR, patients with cardiac LOS were given amrinone (n = 10) or enoximone (n = 9). Following bolus saturation (1.0-2.0 mg/kg [XA = 1.4] or 0.5-1 mg/kg [XE = 0.9] in total), a dose of 5-10 microgram/kg/min was given by infusion. The standard monitoring program included discontinuous haemodynamic measurements (Swan-Ganz) over a maximum time period of 48 hours, arterial and venous blood-gas analyses, and clinical chemistry. The preoperative clinical and haemodynamic status of the enoximone (E) group (55% CABG patients; MPAP 27 +/- 2.5 mmHg, PCWP 20 +/- 2.9 mmHg, PVR 201 +/- 35 dyn.s.cm-5) was considerably worse than that of the amrinone (A) group (70% CABG patients; MPAP 23 +/- 2.3 mmHg, PCWP 16 +/- 3.5 mmHg, PVR 153 +/- 28 dyn.s.cm-5). Both PDE inhibitor preparations led to a significant increase in cardiac index (from 1.9 +/- 0.1 to 2.5 +/- 0.12 L/min/m2 (A) and from 1.98 +/- 0.1 to 2.6 +/- 0.18 L/min/m2 (E) within 30 minutes, accompanied by a simultaneous decrease in filling pressures and vascular resistances. For up to 2 hours, 3/10 (A) and 2/9 (E) patients required additional positive inotropic support with adrenaline. There were no significant differences between the two groups at any time.(ABSTRACT TRUNCATED AT 250 WORDS)

Further studies on the pharmacokinetics of perhexiline maleate in humans

We have performed single-dose pharmacokinetic studies on perhexiline in eight young volunteers, each given 300 mg of Pexid orally, using an h.p.l.c. method for the separation and quantification of the drug and its monohydroxy metabolites in plasma and urine. The plasma concentration of the cis-monohydroxyperhexiline (peak of 473 +/- 43 ng/ml at 7.5 +/- 2.0 h) was always higher than for unchanged perhexiline (peak of 112 +/- 20 ng/ml at 6.5 +/- 2.0 h) whereas the concentration of the transmetabolite was either low or undetectable in plasma. These findings indicate the occurrence of stereospecific pre-systemic metabolism of perhexiline which reduces the bioavailability of the parent drug. The plasma elimination half-life of perhexiline was 12.4 +/- 6.1 h (range 7-23 h) while that for cis-monohydroxyperhexiline was 19.9 +/- 7.7 h (range 10-29 h). Not more than 0.3% of unchanged perhexiline was excreted in the urine over five days in eight subjects. Between 3 and 23% of the orally administered drug was excreted as the cis- or trans-monohydroxy metabolites, the ratio of trans to cis metabolites being 0.52 +/- 0.20.

Investigations of long-term treatment with perhexiline maleate using therapeutic monitoring and electromyography

Experience is reported with 41 patients taking perhexiline maleate for angina pectoris for periods of up to 70 months, while serum concentrations of the drug were monitored, and liver function tests and electromyographic tests were made before and during treatment. Severe side effects did not occur unless serum perhexiline levels were greater than 1.5 mg/L. The drug seems effective for prolonged dosage, and the monitoring of weight, liver function test results, and serum concentrations should prevent or reduce toxicity. A starting dose of 100 mg daily is recommended. The drug is not recommended for routine use in angina pectoris.

Controlled trial of terfenadine and chlorpheniramine maleate in perennial rhinitis

A double-blind clinical trial in 60 patients with perennial rhinitis was conducted to compare the efficacy and side effects of two antihistamines, terfenadine and chlorpheniramine maleate, and placebo. There was no statistically significant difference in response between active treatments and placebo. Although side effects were more frequent with chlorpheniramine this also was not statistically significant.

Impaired oxidation of debrisoquine in patients with perhexiline neuropathy

The use of perhexiline maleate as an antianginal agent is occasionally associated with side effects, particularly neuropathy and liver damage. The reason why some individuals develop these toxic reactions is not clear, though some evidence suggests that they may result from impaired oxidative metabolism, due to genetic or hepatic factors, and consequential accumulation of the drug in toxic concentrations. Drug oxidation was measured with an oxidation phenotyping procedure in 34 patients treated with perhexiline, 20 of whom had developed neuropathy and 14 of whom had not. Most of the 20 patients with neuropathy, but not the unaffected patients, showed an impaired ability to effect metabolic drug oxidation. This impairment was independent of hepatic function, concurrent drug therapy, or tobacco or alcohol consumption. The fact that the ability to oxidise several drugs is genetically controlled points to a genetic susceptibility to developing neuropathy in response to perhexiline. Routine determination of the drug oxidation phenotype might lead to safer use of perhexiline by predicting patients who may be more at risk of developing a neuropathic reaction associated with its long-term use.

Glycylprolyl-p-nitroanilidase in hepatobiliary disease

The serum activity of glycylprolyl-p-nitroanilidase (GPN) has been compared with isocitrate dehydrogenase and with alanine and aspartate aminotransferases in patients with hepatobiliary diseases, myocardial infarction and chronic inflammatory bowel disease. Serum GPN was markedly increased in all hepatobiliary diseases, especially secondary carcinoma and chronic alcoholic hepatitis, but no abnormal values were seen in patients with chronic inflammatory bowel disease. Slightly elevated GPN activities were noticed in a few cases of myocardial infarction. It is suggested that serum GPN would be useful for monitoring hepatic function, especially in the clinical trials of new drug.

Cholera case investigation and the detection and treatment of cholera carriers in Hong Kong

Between 1961 and 1966 cholera cases occurred in Hong Kong in each year except 1965. During this period each case was extensively investigated in order to detect carriers among the contacts.In 1961 investigations were confined to the home of the patient but it was found that a much more extensive investigation was required to get epidemiological information of real value. From 1962 onwards the investigations were extended to include the patient's place of employment or school and any eating-place visited by the patient in the 7 days before the onset of disease.Detection of carriers has been a relatively simple procedure in Hong Kong as it has been the policy to isolate all contacts of a cholera case in a quarantine centre. In 1961 three rectal swabs were taken to detect carriers; this was increased to 5 in 1962 and now 7 consecutive daily swabs are considered necessary. Oral streptomycin is regarded as the best treatment for carriers because it is relatively cheap, it produces no side-effects, treatment can be completed in one day and vibrio resistance to the drug is unlikely.As detailed case investigation is expensive, however, it should be undertaken only if the object is to determine the source of the infection. This object was achieved in Hong Kong on only 6 occasions during the period under review. Isolation of the contacts was of little value in comparison with the disruption of family life and the expense involved. Although regular nightsoil sampling was a good indicator of the presence of the disease, the back-tracing of positive samples occupied facilities and staff which could have been better used in case investigation.

Cholera and nightsoil infection in Hong Kong, 1966

In 1966 there occurred in Hong Kong the rare combination of, in one area, a non-imported case of cholera with no nightsoil infection and, in another area, heavy infection of the nightsoil with no cholera cases. Investigation revealed that there was no connexion between the case (in Kowloon) and the short-lived nightsoil infection (on Hong Kong Island). The hypothesis is advanced that the infection of 5 premises was due to their being visited by a ship's crew, who later left Hong Kong, without the infection spreading to the permanent residents. The authors stress that, in slightly different circumstances and without the existing system of nightsoil monitoring, this infection would not have been detected and cases of cholera might have occurred with no forewarning.