Effects of cigarette smoke inhalation on plasma diltiazem levels in rats.
A rapid and sensitive method for the assay of plasma diltiazem was developed using a solid-phase extraction technique followed by high-performance liquid chromatography. The effects of cigarette smoke on plasma levels of orally administered diltiazem was investigated in rats. The animals were exposed to cigarette smoke for 10 min using a Hamburg II smoking machine, immediately after oral administration of diltiazem (10 mg/kg). In the nonsmoking nonrestrained rats, plasma diltiazem levels increased rapidly and reached the maximum (7.1 micrograms/kg) 2 h after administration and decreased gradually thereafter. In the nonsmoking restrained rats, plasma diltiazem levels increased rapidly, but showed almost constant levels between 1 h and 8 h after administration. The maximum level (5.4 micrograms/kg) was shown after 2 h. On the other hand, plasma diltiazem levels in the rats exposed to cigarette smoke reached the maximum (4.3 micrograms/kg) after 4 h. These results suggest that absorption of orally administered diltiazem is inhibited and delayed by cigarette smoke.
Matsuka
N
N
Department of Hospital Pharmacy, Okayama University Medical School, Japan.
Furuno
K
K
Eto
K
K
Oishi
R
R
Gomita
Y
Y
D000818:Animals; D002317:Cardiovascular Agents / Q000097:blood* / Q000493:pharmacokinetics; D004110:Diltiazem / Q000097:blood* / Q000493:pharmacokinetics; D008297:Male; D009538:Nicotine / Q000494:pharmacology; D010947:Plants, Toxic; D051381:Rats; D017208:Rats, Wistar; D012906:Smoke / Q000009:adverse effects*; D012907:Smoking / Q000009:adverse effects / Q000097:blood*; D014026:Nicotiana
D002317:Cardiovascular Agents; D012906:Smoke; D009538:Nicotine; D004110:Diltiazem