Pharmacokinetics and pharmacodynamics of verapamil following sublingual and oral administration to healthy volunteers.

1. The pharmacokinetics and pharmacodynamics of verapamil administered via the oral and sublingual routes were compared in a randomised, two-way cross-over study involving six healthy male volunteers. 2. Administered sublingually, a verapamil 40 mg (Securon) crushed tablet produced a significantly higher peak plasma concentration (P less than 0.05), a greater rate of absorption (P less than 0.05), and greater bioavailability (P less than 0.05) when compared with orally administered verapamil 40 mg (Securon). 3. In comparison with oral dosing, PR intervals were significantly (P less than 0.05) prolonged between 30 and 90 min after sublingual verapamil dosing. 4. Correlations between log plasma verapamil concentration and percentage increase in PR interval were greater after sublingual compared with oral dosing in all volunteers.