Pharmacokinetic Interaction Among Telmisartan, Amlodipine, and Hydrochlorothiazide After a Single Oral Administration in Healthy Male Subjects.

PURPOSE

Hypertension is a major risk factor for cardiovascular diseases, necessitating hypertension control. Antihypertensive drugs are more potent when administered in combinations of 2 or 3 different classes of drugs. One such therapy includes a combination of an angiotensin receptor blocker, a calcium channel blocker, and a diuretic. The objective of this study was to evaluate the pharmacokinetic interaction among telmisartan, amlodipine, and hydrochlorothiazide.

METHODS

A randomized, open-label, 3-period, 6-sequence, 3-treatment, single-dose crossover study was conducted in healthy male subjects. Subjects were randomly assigned to 1 of 6 sequences and one of the following treatments was administered in each period: treatment A, co-administration of one tablet of telmisartan 80 mg and one tablet of amlodipine 10 mg; treatment B, one tablet of hydrochlorothiazide 25 mg alone; and treatment C, co-administration of all 3 investigational products. Serial blood samples were collected up to 144 hours postdose. Plasma drug concentrations were measured by using LC/MS-MS. Pharmacokinetic parameters, including C and AUC, were determined by using noncompartmental analysis. The geometric least squares mean ratios and associated 90% CIs of log-transformed C and AUC for separate administration or co-administration were calculated to evaluate pharmacokinetic interactions.

FINDINGS

Twenty-seven subjects completed the study. The geometric least squares mean ratios and 90% CIs of C and AUC were 1.02 (0.85-1.21) and 1.04 (0.97-1.13) for telmisartan; 1.00 (0.95-1.04) and 0.95 (0.91-0.99) for amlodipine; and 0.88 (0.82-0.96) and 0.86 (0.82-0.90) for hydrochlorothiazide, respectively. No serious adverse events were recorded, and all reported adverse events were of mild intensity.

IMPLICATIONS

The pharmacokinetic parameters of telmisartan, amlodipine, and hydrochlorothiazide when administered separately or co-administered were compared, and all the parameters met the criteria for pharmacokinetic equivalence. Combination therapy of these 3 drugs had no significant impact on the pharmacokinetic parameters of each drug. (ClinicalTrials.gov Identifier: NCT03889145).