Modification of propranolol's bioavailability by Eurycoma longifolia water-based extract.

WHAT IS KNOWN AND BACKGROUND: Eurycoma longifolia (E. longifolia), a herb commonly consumed for its aphrodisiac properties, is widely used by Asian males. This may include hypertensive patients receiving propranolol which may cause sexual dysfunction as one of its side-effects. There is no published study of the potential pharmacokinetic interaction between propranolol and the herb. OBJECTIVE: To study propranolol's pharmacokinetics when E. longifolia is consumed, comparing volunteers given either propranolol or a placebo. METHODS: This is a placebo-controlled randomized single-blinded crossover study of the effect of a water-based extract of E. longifolia on the pharmacokinetics of a single dose of proporanolol (Inderal(®)) in 14 healthy non-smoker young males. Eighty milligram of propranonol was orally administered with (i) placebo (Lactose) or (ii) 200 mg of water-based extract of E. longifolia (0·0272 ± 0·0026%eurycomanone) following an overnight fasting. Blood samples were collected at 0, 0·5, 1, 1·5, 2, 3, 4, 6, 8 and 10 h for propranolol's plasma concentration determinations using a validated high-performance liquid chromatography (HPLC) method. RESULTS AND DISCUSSION: When propranolol was administered with E. longifolia, its bioavailability (AUC0-∞) decreased by 29% while C(max) was reduced by 42% and T(max) was significantly prolonged by almost 86%. The terminal elimination half-life, however, was not significantly affected. CONCLUSION: The bioavailability of propranolol is significantly decreased when consumed together with E. longifolia. The interaction is due to a reduction in absorption, rather than an increase in propranolol's metabolism. Although the pharmacodynamics of propranolol was not affected in healthy volunteers, caution is still advisable with co-administration of the drug and the herb.

The association between pre-morbid conditions and respiratory tract manifestations amongst Malaysian Hajj pilgrims

In a very closed and overcrowding environment, influenza transmission during Hajj season is almost inevitable. The aim of this study was to determine the association between pre-morbid conditions and influenza-like illness (ILI) amongst Hajj pilgrims. A cross-sectional study was conducted amongst Malaysian Hajj pilgrims in year 2007. Survey forms were distributed at Madinatul-Hujjaj, Jeddah and Tabung Haji Clinic, Medina, Saudi Arabia where pilgrims stay on transit before returning to Malaysia. Allergic rhinitis was significantly associated with sore throat (p=0.047), longer duration of cough (p= 0.017) and runny nose (p=0.016). Pilgrims who suffered from chronic obstructive pulmonary diseases (COPD) had significant association with longer duration of cough (p=0.041) and those with diabetes mellitus had significant association with longer duration of sore throat (p=0.048). Underlying asthma was significantly associated with severe influenza like illness requiring admission to hospital for further treatment of respiratory symptoms (p=0.016). Based on these findings, we suggest those with underlying asthma should be discouraged from participating in the hajj and they should seek early treatment if they develop respiratory symptoms.

Suppression of hypotensive responses of captopril and enalapril by the kallikrein inhibitor aprotinin in spontaneously hypertensive rats.

The present investigation evaluated the effects of aprotinin, an inhibitor of kallikrein, on blood pressure responses, heart rate, and duration of hypotension induced by acute administration of captopril and enalapril (angiotensin-converting enzyme inhibitors) in anaesthetized spontaneously hypertensive rats. Captopril (20 mg/kg) and enalapril (20 mg/kg) administered intravenously caused a significant (p < 0.001) fall in systolic and diastolic blood pressures in the absence of aprotinin. In contrast, captopril (20 mg/kg) and enalapril (20 mg/kg) failed (p > 0.05) to cause a fall in systolic and diastolic blood pressures in the presence of aprotinin (2 mg/kg). Captopril and enalapril were able to significantly reduce the heart rate (p < 0.05 and p < 0.001) in the presence as well as in the absence of aprotinin. The duration of hypotension produced by captopril and enalapril was abolished significantly (p < 0.001) in the presence of aprotinin. These findings may suggest that captopril and enalapril caused hypotension via the kallikrein pathway, since the kallikrein inhibitor aprotinin can antagonize the hypotensive responses of these agents. Thus, kallikrein may be an independent mediator in the regulation of blood pressure.