Treatment of the common cold

BACKGROUND

Common colds are usually treated by the patients themselves with over-the-counter (OTC) cold medications. Many cough and cold remedies are available and sold freely without prescription. The authors conducted a study to compare the efficacy, adverse effects, the quality of life (QOL) and the patient's opinion and appreciation on the drugs (POD) between Dayquil/Nyquil and Actifed DM plus paracetamol syrup.

METHOD

In this prospective, investigator-blinded clinical trial, 120 patients, aged between 15 and 60 years old, with common colds within 72 hours, who accepted the trial and gave informed written consent, were randomized into two treatment groups. One patient was excluded due to evidence of bacterial infection. Fifty-nine patients were treated with Dayquil/Nyquil (D/N group), while the other 60 patients had Actifed DM plus paracetamol (ADM/P group) for three days. On day 1 the patient's demographic data (sex, age, body weight, blood pressure, co-existing diseases/conditions, drug use, and allergy to any drugs), the most prominent symptoms and its duration were recorded. All patients were screened for bacterial infection by physical examination, complete blood count and sinus radiographs. The symptoms (nasal obstruction, rhinorrhea, sneezing, cough, sore throat, fever and headache) and signs (injected nasal mucosa, nasal discharge and pharyngeal discharge) were scored, based on 4-point scale (0 to 3), on days 1 and 4. Changing of the symptoms and QOL were recorded on the diary card. The patient's opinion and appreciation on the drugs (POD) was assessed on day 4. The effectiveness (the ability to lessen the symptoms and signs), QOL and POD between two treatments were compared.

RESULTS

The demographic data between the two groups were similar. The four most common prominent symptoms of common colds in our series were cough (47.9%), sore throat (26.17%), rhinorrhea (8.4%) and headache (8.4%). However, both treatments were equally effective in lessening the symptoms (P = 0.426) and signs (P = 0.716) of common cold from days 1 to 4. The adverse effects were significantly higher in ADM/P group than in D/N group (p = 0.006). In contrast, QOL in terms of alertness, freshness and sound sleep improved from day 1 to day 3 in both treatments, but the overall day-3 score was significantly higher in the D/N group than the ADM/P group (1.85 +/- 1.83; 1.25 +/- 1.94: p = 0.024). POD in terms of convenience, flavour of drug, effectiveness of the drug and a need to repeat the drug assessed on day 4, was also significantly higher in the D/N group than the ADM/P group (10.68 +/- 2.56; 8.92 +/- 2.27: p < 0.001).

CONCLUSION

Dayquil/Nyquil are as effective as Actifed DM plus paracetamol in controlling the symptoms and signs of the common cold, but have fewer adverse effects. The quality of life assessed during the use of the drugs was significantly higher in the Dayquil/Nyquil group, and according to the patients, they prefered Dayquil/Nyquil more than Actifed DM plus paracetamol.

Cardiotoxicity of new antihistamines and cisapride

Although the new second-generation nonsedative antihistamines terfenadine and astemizole were launched as highly selective and specific H(1)-receptor antagonists, they were later found to cause prolongation of the QT-interval and severe cardiac arrhythmias. The prolongation of the QT-interval is caused by the blockade of one or more of the cardiac potassium channels, among which the delayed rectifier I(Kr), encoded by the HERG-gene, appears to be the most significant. The potency of the prokinetic drug cisapride to block I(Kr) appears to be similar to that of terfenadine (IC(50) about 50 nmol/l). These drugs cause problems when overdosed, used in combination with inhibitors of their CYP3A4-mediated metabolism, or when given to individuals with altered drug kinetics (the aged) or patients with existing cardiac disease (congenitally long QT). Moreover, interactions with other QT-interval prolonging drugs require special attention. Active hydrophilic metabolites of the second-generation antihistaminic compounds (ebastine-carebastine, loratadine-desloratadine, terfenadine-fexofenadine, astemizole-norastemizole) are new compounds with probably reduced risk for drug interactions and cardiac toxicity.

Sedation with "non-sedating" antihistamines: four prescription-event monitoring studies in general practice

OBJECTIVES

To investigate the frequency with which sedation was reported in post-marketing surveillance studies of four second generation antihistamines: loratadine, cetirizine, fexofenadine, and acrivastine.

DESIGN

Prescription-event monitoring studies.

SETTING

Prescriptions were obtained for each cohort in the immediate post-marketing period.

SUBJECTS

Event data were obtained for a total of 43 363 patients.

MAIN OUTCOME MEASURES

Reporting of sedation or drowsiness.

RESULTS

The odds ratios (adjusted for age and sex) for the incidence of sedation were 0.63 (95% confidence interval 0.36 to 1.11; P=0.1) for fexofenadine; 2.79 (1.69 to 4.58; P<0.0001) for acrivastine, and 3.53 (2.07 to 5.42; P<0.0001) for cetirizine compared with loratadine. No increased risk of accident or injury was evident with any of the four drugs.

CONCLUSIONS

Although the risk of sedation was low with all four drugs, fexofenadine and loratadine may be more appropriate for people working in safety critical jobs.

Inhibition of histamine or allergen-induced wheals by a single dose of acrivastine, fexofenadine or cetirizine

Certirizine, a potent H1-blocking agent, is often recommended as an emergency drug in anaphylactic reactions because of its well documented fast onset of action. In this randomized, cross-over study we compared the onset of action after a single dose of two recently introduced antihistamines, acrivastine and fexofenadine, with that of cetirizine. The inhibition of the wheal-and-flare reaction produced by skin prick test with histamine in 20 healthy volunteers and with a relevant pollen allergen in 20 atopic patients, respectively, were measured before and at regular intervals up to 60 min after the ingestion of acrivastine (8 mg and 16 mg), fexofenadine (120 mg) and cetirizine (10 mg and 20 mg). Wheal-and-flare reaction were significantly inhibited 20 min after the intake of 16 mg acrivastine in atopic patients and 30 min after intake of 8 mg acrivastine in healthy volunteers, whereas cetirizine produced a significant inhibition of the wheal-and-flare reaction within 40-60 min. No significant inhibition could be observed within 60 min after fexofenadine intake. Therefore, in clinical settings when a fast onset of the H1-blocking action is mandatory (e.g., after insect stings or for short-term prophylaxis) we recommend acrivastine.

Risk of ventricular arrhythmias associated with nonsedating antihistamine drugs

AIMS

To quantify and compare the incidence of ventricular arrhythniias associated with the use of five nonsedating antihistamines: acrivastine, astemizole, cetirizine, loratadine and terfenadine. The effects of age, sex, dose, duration of treatment, and the interaction with P450 inhibitor drugs were also examined.

METHODS

We carried out a cohort study with a nested case-control analysis using the UK-based General Practice Research database (GPRD). The study cohort included persons aged less than 80 years old who received their first prescription for any of the five study drugs between January 1, 1992 and September 30, 1996. We estimated relative risks and 95% confidence intervals of idiopathic ventricular arrhythmias with current use of antihistamines as compared with non use.

RESULTS

The study cohort included 197425 persons who received 513012 prescriptions. Over the study period 18 valid cases of idiopathic ventricular arrhythmias were detected. Nine occurred during the current use of any antihistamine, resulting in a crude incidence of 1.9 per 10000 person-years (95%CI: 1.0-3.6) and a relative risk of 4.2 (95%CI: 1.5-11.8) as compared with non use. Astemizole presented the highest relative risk (RR= 19.0; 95%CI: 4.8-76.0) of all study drugs, while terfenadine (RR=2.1; 95%CI:0.5-8.5) was in the range of other nonsedating antihistamines. Older age was associated with a greater risk of ventricular arrhythmias (RR=7.4; 95%CI: 2.6-21.4) and seemed to increase the effect of antihistamines (RR=6.4; 95%CI: 1.7-24.8). The proportions of high dose terfenadine and the concomitant use with P450 inhibitors among current users of terfenadine were 2.7% and 3.4%, respectively over the study period with no single case of ventricular arrhythmias occurring in the presence of these two risk factors.

CONCLUSIONS

The use of nonsedating antihistamines increases the risk of ventricular arrhythmias by a factor of four in the general population. Yet, the absolute effect is quite low requiring 57000 prescriptions, or 5300 person-years of use for one case to occur. The risk associated with terfenadine was no different from that with other nonsedating antihistamines.

Efficacy of acrivastine plus pseudoephedrine for symptomatic relief of seasonal allergic rhinitis due to mountain cedar

BACKGROUND

Acrivastine is a second-generation H1-antagonist chemically related to triprolidine, but more polar and with less central nervous system penetration than triprolidine.

OBJECTIVE

The efficacy of the antihistamine-decongestant combination product (Semprex-D capsules) containing acrivastine 8 mg plus pseudoephedrine HCl 60 mg was evaluated for the treatment of seasonal allergic rhinitis symptoms.

METHODS

A total of 676 patients sensitive to mountain cedar pollen was enrolled into a 6-center, randomized, double-blind, placebo-controlled, parallel, 4-group study designed to compare acrivastine + pseudoephedrine, acrivastine, pseudoephedrine, and placebo. Patients with demonstrable diary symptom scores at baseline took study medication (4 doses/day) and recorded symptom scores twice daily for 2 weeks. The effectiveness of the acrivastine + pseudoephedrine combination was examined relative to the individual components and placebo in terms of changes in diary symptom scores.

RESULTS

Over the 2-week period, the combination of acrivastine plus pseudoephedrine was significantly more effective than (1) acrivastine, pseudoephedrine, and placebo (P < .001) for relief of all symptoms; (2) pseudoephedrine (P < .001) for relieving allergy symptoms, ie, running nose, sneezing, itchy nose/throat and tearing; and (3) acrivastine (P < .001) for reducing nasal congestion. Relative to placebo, small increases in adverse experience rates were observed with acrivastine + pseudoephedrine for dry mouth, insomnia, somnolence, and headache.

CONCLUSION

These findings in a large clinical trial demonstrate (1) the efficacy of acrivastine and (2) that each component of the combination of acrivastine 8 mg plus pseudoephedrine HCl 60 mg contributes to the overall efficacy, thereby supporting the conclusion that the combination is rational, safe, and effective for the treatment of allergic rhinitis.

Comparison of the effects of astemizole/pseudoephedrine and triprolidine/pseudoephedrine on CNS activity and psychomotor function

The sedative properties of astemizole-D and triprolidine-D were compared in a double-blind, placebo-controlled, repeated-measures design study comprising three experimental treatments, each with a duration of 2 days (n = 12). Sedation was assessed by continuous electroencephalographic measurement (C-EEG), intermittent performance testing and subjective measures. C-EEG monitoring revealed that triprolidine-D produced significantly more daytime sedation and drowsiness than either astemizole-D or placebo (p < 0.05). Intermittent performance testing did not reveal consistent psychomotor deficits. There were no differences from placebo; the only significant findings showed that astemizole-D improved tracking accuracy at T + 65 h (p < 0.05) compared to baseline. Also, when scores were summed across all time points, astemizole-D improved scores significantly in contrast to triprolidine-D for the total scores (p < 0.05). It is concluded that, in contrast to triprolidine-D, astemizole-D does not produce daytime drowsiness or sedation.

Efficacy of acrivastine with pseudoephedrine in treatment of allergic rhinitis due to ragweed

BACKGROUND

Semprex-D capsules contain acrivastine 8 mg (a second generation H1-antagonist) plus pseudoephedrine HCl 60 mg and were developed to satisfy the needs of allergy suffers who prefer combination products designed to provide broader symptom relief. Approval of combination products by the US Food and Drug Administration requires demonstration that each component contributes to the overall effectiveness.

OBJECTIVE

The objective of the study was to demonstrate that both acrivastine and pseudoephedrine share in the efficacy of the combination in relieving allergy symptoms in patients sensitive to ragweed pollen.

METHODS

This was a double-blind, randomized, placebo-controlled, parallel groups, balanced design, multicenter (13 sites) study. Patients 12 years of age or older with skin test reactivity to ragweed were recruited. Patients who qualified for the study were dispensed either (1) acrivastine + pseudoephedrine, (2) acrivastine, (3) pseudoephedrine, or (4) placebo with instructions to take one capsule 4 times daily and to record allergy symptom scores in a symptom diary 3 times daily for 14 days. Assessments of health, global allergy symptoms, protocol compliance, adverse events, and vital signs were also documented.

RESULTS

A total of 702 patients were enrolled in this study. Over the 2-week period, the combination of acrivastine + pseudophedrine was significantly more effective than acrivastine, pseudoephedrine, and placebo for relief of all symptoms (P range .01 to .001); pseudoephedrine for treating symptoms responsive to antihistamines (P = .003); and acrivastine for treating symptoms responsive to nasal decongestants (P < .001). Relatively small increases in adverse experience rates were observed for the combination relative to the placebo.

CONCLUSIONS

These findings in a large clinical trial demonstrate that each component of the combination of acrivastine 8 mg plus pseudoephedrine HCl 60 mg contributes to the overall efficacy, thereby supporting the conclusion that the combination is rational, safe, and effective for the treatment of allergic rhinitis.

Antihistamine effects on actual driving performance in a standard test: a summary of Dutch experience, 1989-94

The review summarizes the major results of eight double-blind, placebo-controlled, volunteer studies undertaken by three independent institutions for showing the effects on actual driving performance of "sedating" and "nonsedating" antihistamines (respectively, triprolidine, diphenhydramine, clemastine and terfenadine, loratadine, cetirizine, acrivastine, mizolastine, and ebastine). A common, standardized test was used that measures driving impairment from vehicular "weaving" (i.e., standard deviation of lateral position (SDLP)). Logical relationships were found between impairment and dose, time after dosing, and repeated doses over 4-5 days. The newer drugs were generally less impairing, but differences existed among their effects, and none was unimpairing at doses 1-2x the currently recommended levels. One or possibly two of the newer drugs possessed both performance-enhancing and -impairing properties, depending on dose, suggesting two mechanisms of action.

Acrivastine, terfenadine and diphenhydramine effects on driving performance as a function of dose and time after dosing

The study was conducted according to a nine-way, observer- and subject-blind, cross-over design. Its purpose was to compare the single-dose effects of the following drugs on driving performance: acrivastine (8, 16 and 24 mg); the combination of acrivastine (8 mg) with pseudoephedrine (60 mg); terfenadine (60, 120 and 180 mg); diphenhydramine-HCl (50 mg); and placebo. The subjects were 18 healthy female volunteers. Drug effects were assessed in two repetitions of two driving tests (highway driving and car-following) after each treatment. Acrivastine's impairing effects in both driving tests were similarly dose-related. The 8-mg dose had a small, but significant, effect on highway driving in the first trial. The 16-mg and 24-mg doses significantly impaired driving in both tests during the first trial and the 24-mg dose did so again during the second trial. Neither the combination of acrivastine with pseudoephedrine nor terfenadine caused any significant impairment of performance. Diphenhydramine significantly impaired driving in both tests during every trial. In conclusion, the normal therapeutic dose of acrivastine (8 mg) had little effect on driving performance, and virtually none when that dose was given in combination with pseudoephedrine (60 mg). Higher doses of acrivastine severely impaired driving performance. Terfenadine had no significant effect on driving performance after any dose while diphenhydramine strongly impaired every important driving parameter.

Effects of acrivastine and terfenadine on skin reactivity to histamine

The response to the histamine hydrochloride prick skin test was studied in 24 healthy volunteers who received, in random order and at least four days apart, acrivastine (8 mg), terfenadine (120 mg), and placebo. The tests were performed on either side of the back before and at the time of administration (single dose), then every 30 minutes for two hours, and every hour for the following four hours. Evaluation was based on the mean of two measurements of the surface area of the wheal-and-flare reaction accompanied by assessment of topical pruritus. The response to histamine was decreased markedly in the two active treatment groups. Although within one hour of injection, the activity of both antihistamines was consistently greater than that of placebo, the kinetics of action of the two products nevertheless differed; indeed acrivastine was active against flare and wheal earlier (within 30 minutes); terfenadine proved to be more active than acrivastine only on flare and only at the later times (four, five, and six hours). The safety study primarily demonstrated drowsiness in one-fourth of the patients receiving placebo and active treatment.

A cross-over comparison of acrivastine, pseudoephedrine and their combination in seasonal allergic rhinitis

In a four period, double-blind cross-over study, forty patients with moderate to severe symptoms of seasonal allergic rhinitis received in randomised order 8 mg acrivastine, 60 mg pseudoephedrine, 8 mg acrivastine plus 60 mg pseudoephedrine and placebo. Each treatment was given three times daily for six days with a one day washout period between treatments. Acrivastine alone significantly reduced all the symptom severity scores when compared to placebo or pseudoephedrine alone (p less than 0.01). These severity scores were assigned daily by patients for itchy nose/throat, sneezing, running nose, blocked nose, watery eyes, itchy eyes and overall symptoms. The combination of acrivastine and pseudoephedrine was significantly better than either placebo or pseudoephedrine alone in controlling all symptom scores (p less than 0.01) and it was also superior to acrivastine alone (p less than 0.05) in controlling all symptoms except itchy eyes. The results confirm the expected additive rather than synergistic effect of acrivastine and pseudoephedrine in combination. The control of symptoms assessed at the end of each treatment period was considered either excellent or good by 79% of patients and 84% of investigators for acrivastine plus pseudoephedrine and, for acrivastine alone, by 69% of patients and 67% of investigators. Both acrivastine alone and acrivastine and pseudoephedrine in combination were well tolerated. There was no significant difference in the number of adverse experiences reported in either of these two groups compared to the number of adverse experiences reported in the placebo group.

Acrivastine in seasonal allergic rhinitis: two randomized crossover studies to evaluate efficacy and safety

In two randomized crossover studies, the antihistamine, acrivastine, was evaluated for the treatment of seasonal allergic rhinitis. One study on 31 patients found both 4 and 8 mg acrivastine given three times daily to be significantly better than placebo for alleviating hay fever. There were no significant differences in symptom scores between the two doses, although more patients (63%) favoured 8 mg acrivastine over the 4 mg dose (46%) or placebo (35%). The other study found the higher dosage regimen to be similar in efficacy to 1 mg clemastine given three times daily. Both dosages were significantly better than placebo for reducing symptom scores in all 18 evaluable patients. The incidence of adverse experiences was low in both studies; there being no dose-related effects of acrivastine. In the second study, drowsiness, probably or possibly treatment related, occurred on seven occasions during clemastine treatment and once with acrivastine. These studies indicate that 8 mg acrivastine given three times daily is both well tolerated and of equal efficacy to clemastine for the treatment of seasonal allergic rhinitis.

Comparison of the new antihistamine acrivastine (BW 825C) versus cyproheptadine in the treatment of idiopathic cold urticaria

A double-blind, crossover trial with a new triprolidine derivative, acrivastine (BW 825C; 8 mg 3 times daily), cyproheptadine (4 mg 3 times daily) and placebo was carried out in 18 patients suffering from idiopathic cold urticaria. Acrivastine and cyproheptadine significantly (p less than 0.01) reduced weal areas following ice cube challenge when compared to placebo. Acrivastine was found to be significantly more effective (p less than 0.01) than cyproheptadine in reducing weal areas. Furthermore, cyproheptadine caused significantly more drowsiness than acrivastine (p = 0.021) or placebo (p = 0.013), which did not differ from each other. This study shows that acrivastine is an effective agent in the treatment of cold urticaria and suggests that acrivastine in the dose used lacks adverse effects, such as drowsiness, traditionally associated with antihistamine therapy.

Effects of triprolidine and dipipanone in the cold induced pain test, and the central nervous system of healthy volunteers

1 Twelve healthy volunteers took part in a study of the interaction between the antihistamine triprolidine and the opioid dipipanone in the cold induced pain (CP) test and tests of sedation. They received placebo, triprolidine 2.5 mg, dipipanone 8 mg or the combination of the two active treatments according to a double-blind, randomised, balanced, crossover design. 2 Antihistamine activity was demonstrated by triprolidine reducing the size of wheals and flares produced by intradermal histamine 1.6 micrograms. However, triprolidine produced no analgesia in the CP test, nor did it enhance the analgesia produced by dipipanone alone. 3 Neither treatment alone produced statistically significant sedation, assessed by visual analogue scales (VAS), side effect check list, body sway and reaction times. However, the combination did cause significant sedation. 4 Dipipanone reduced pupil size, depressed respiration, and decreased salivation. Triprolidine had no effects on pupil size and respiration, but reduced salivation slightly. It was concluded that histaminergic (H1) mechanisms are unlikely to be involved in pain produced by cold.

Effects of a mu-opioid receptor agonist (codeine phosphate) on visuo-motor coordination and dynamic visual acuity in man

Effects of codeine (30, 60 and 90 mg) on visuo-motor coordination and dynamic visual acuity, together with critical flicker fusion, digit symbol substitution, complex reaction time and subjective assessments of mood, were studied from 0.75-2.0 h after ingestion by six healthy female adults. The study was double-blind and placebo controlled, and triprolidine (10 mg) was used as the active control. The effect on visuo-motor coordination was limited and was dose related and linear, and performance was altered on visuo-motor coordination with 60 and 90 mg codeine, and on dynamic visual acuity with 90 mg codeine (P less than 0.05). No other effect of codeine was detected. Modulated neuromuscular function is likely to be the common denominator of the changes in performance with codeine, though nausea, but not sedation, may be a contributory factor. It is possible that altered performance with codeine may involve interactions with different receptors than those which lead to sedation.

An investigation of the H1-receptor antagonist triprolidine: pharmacokinetics and antihistaminic effects

A single oral dose of triprolidine hydrochloride, 0.04 mg/kg (mean dose 2.7 +/- SD 0.4 mg) was administered to seven healthy, fasting adult volunteers who had never been treated previously with H1-receptor antagonists. Blood sampling and intradermal tests with 0.01 ml of histamine phosphate (0.1 mg/ml) were performed at -0.25, 1, 2, 3, 4, 5, 6, 7, 8, and 12 hours after the dose. Wheal-and-flare circumferences were traced, and the areas were measured by planimetry. Pruritus was quantitated by use of a clinical score. Urine was collected in 6-hour pooled aliquots for a total of 24 hours. Serum and urine triprolidine concentrations were measured by high-performance liquid chromatography. Wheal-and-flare areas and pruritus decreased after the triprolidine dose. Suppression of mean flare size was statistically significant at 2, 3, 6 and 8 hours. Suppression of mean wheal size was not statistically significant at any time compared to predose values. The mean triprolidine serum half-life was 2.1 +/- 0.8 hours. The mean peak serum triprolidine concentration of 15.4 +/- 8.3 ng/ml occurred 2 hours after ingestion. No triprolidine was detected in the serum after 12 hours. The mean urinary excretion of unchanged triprolidine during 24 hours was 1.3 +/- 1.0% of the dose administered.

The acute effects of acrivastine (BW825C), a new antihistamine, compared with triprolidine on measures of central nervous system performance and subjective effects

The new H1-antagonist acrivastine (BW825C) in doses of 4, 8, and 16 mg was compared with triprolidine HCl (2.5 and 5 mg) in a double-blind crossover study in 12 subjects. Adaptive tracking performance 1.5 hours after dosing was impaired by triprolidine, 2.5 and 5 mg; the impairment was still detectable 3.5 hours after 5 mg. Acrivastine did not impair adaptive tracking after any of the doses. Triprolidine increased reaction times after 1.5 hours (2.5 and 5 mg) and 3 hours (5 mg), but acrivastine did not have any effect on reaction time at any dose. Both doses of triprolidine caused subjective central nervous system effects after 1.5 hours, and triprolidine, 5 mg, still had some detectable effects on subjective rating scales after 3 hours. No subjective effects were noted after acrivastine. We conclude that acrivastine at doses causing more peripheral H1-antagonism than triprolidine has considerably reduced central nervous system activity.

Randomized single-blind trial in general practice comparing the efficacy and palatability of two cough linctus preparations, 'Pholcolix' and 'Actifed' Compound, in children with acute cough

Two hundred and seventeen patients between 6 and 12 years of age suffering from acute cough took part in a randomized, single-blind study comparing 'Pholcolix' and 'Actifed' Compound. No significant difference in efficacy was demonstrated but analysis of palatability components (taste, smell, aftertaste and feeling in the mouth) showed numerical superiority for 'Pholcolix' for all parameters, with a high degree of significance for overall taste. 'Pholcolix' caused significantly fewer side-effects, with 'Actifed' Compound causing markedly more drowsiness after daytime dosage.

Cardiorespiratory assessment of decongestant-antihistamine effects on altitude, +Gz, and fatigue tolerances

Decongestants and antihistamines are known to produce effects capable of adversely modifying physiological function and psychomotor task performance. Because of relevance to safe pilot performance, the effects of single doses of two decongestant-antihistamine preparations (Compound A and Compound B), or a placebo on cardiorespiratory responses to two equally spaced +2 Gz tests during separate 2-h exposures at 388 m (1,274 ft MSL) ground level (GL) and 3,810 m (12,500 ft) chamber altitude were assessed. Post-altitude fatigue was assessed by cardiorespiratory responses to submaximal bicycle ergometry. Compound A and Compound B appeared to exert no significant detrimental effects on short-duration post-altitude ergometric fatigue-ability. With two exceptions, all combinations of medication, altitude, and +Gz were well tolerated. Two subjects were clearly incapacitated during the first +2 Gz test under Compound A at 3,810 m (12,500 ft) altitude. It is felt that the +Gz-intolerance resulted mainly from an adverse interactive effect of Compound A and altitude on vasomotor and/or chronotropic mechanisms.

A Double-blind crossover trial of pseudoephedrine and triprolidine, alone and in combination, for the treatment of allergenic rhinitis

In a double-blind crossover trial of pseudoephedrine 60 mg and triprolidine 2.5 mg, alone and in combination, on 40 volunteers suffering from allergic rhinitis, both drugs were found superior to placebo in reducing the effects of allergic rhinitis and were of equal efficacy. The combination tablet was consistently better than either drug in several of the assessments and was the treatment which the subjects, as a whole, preferred. Side effects were not a problem with any of the medications.