Liver function tests and low-dose estrogen oral contraceptives

Twenty healthy female volunteers were treated with 35 microgram ethinyl estradiol and 0.4 mg norethindrone for a two-month period of time. Liver function tests (serum SGOT, SGPT, LDH, alkaline phosphatase, total bilirubin, total protein, albumin and prothrombin times) were measured at baseline and control prior to treatment, and at one and two months of therapy. There was a 1.25% incidence of abnormalities in the 320 tests conducted during therapy. During the first month of therapy, there was a 1.9% incidence of abnormal tests. 0.625% incidence of abnormal tests was seen in the second month of treatment. A 5% incidence of abnormalities (single episodes in each parameter) was seen in SGPT, LDH, total bilirubin and prothrombin time levels during the two-month period. This was well below the 10-30% incidence of abnormalities reported with 50-100 microgram of estrogen-containing birth control pills in previous studies. There seems to be little effect on liver function tests with use of estrogen preparations containing 35 microgram ethinyl estradiol.

Efficacy of estradiol vaginal cream in postmenopausal women

In a double-blind parallel study daily intravaginal administration of conjugated estrogen cream and estradiol cream for 14 days relieved vasomotor and vaginal postmenopausal symptoms in 29 postmenopausal women. By day 14, therapy with the estradiol vaginal cream resulted in plasma estrone and estradiol levels closer to those in premenopausal women than therapy with the conjugated estrogen cream. The extent of improvement and final estradiol plasma levels in the estradiol vaginal-cream group correlated. There was no correlation with severity of symptoms or estradiol plasma level at baseline. The metabolism of the conjugated estrogen cream might account for absence of correlation between improvement and final estradiol plasma levels in the conjugated vaginal-cream group.

Dose tolerance and pharmacokinetic studies of L (+) pseudoephedrine capsules in man

Dose tolerance and pharmacokinetic studies of pseudoephedrine sustained action capsules were performed in thirty-three adult male subjects who received either 120 mg or 150 mg capsules every twelve hours for seven consecutive days in a double-blind parallel design study. Although only one subject in the 150 mg group was discontinued prematurely from this study, a large number of side effects typical of CNS stimulation were seen. A placebo effect might account for a portion of these complaints, however symptoms evaluated as being due to drug were significantly more severe and persistent in the 150 mg group. Pulse rates showed a persistent and significant increase while systolic and diastolic blood pressure fell from the baseline values in both groups. A pharmacokinetic analysis of the pseudoephedrine plasma concentration-time data provided estimates of half-life and the volume of distribution/availability ratio. The values obtained were in good agreement with values reported by others. Half-life was not influenced by urine pH probably as a result of the narrow range of urine pHs observed in the subjects. Calculations of relative bioavailability suggest that the 120 mg capsule formulation has a 30% greater bioavailability compared to the 150 mg capsule.

Digoxin bioavailability: formulations and rates of infusions

The bioavailability of digoxin (lanoxin) tablets, oral aqueous solution of digoxin, and capsules containing a solution of digoxin was compared with digoxin given intravenously over 1 and 3 hr. The mean peak serum concentration of digoxin after the 1-hr intravenous infusion was 5 ng/ml, after the 3-hr infusion, 3.5 ng/ml, and after the oral solution, 2.0 ng/ml. There was an equivalent bioavailability of the oral solution and reference tablets of digoxin. The digoxin in capsules tended to be better absorbed than the reference tablets. There was 21% more digoxin excreted over 6 days after the 3 hr iv infusion than after the 1 hr iv infusion. This indicates that the calculated bioavailability of an orally administered dose of digoxin may vary with the rapidity of injection of the intravenous standard. It is estimated that an oral tablet of digoxin of 0.5 mg has about the same bioavailability as 0.35 of digoxin given by slow intravenous infusion (or 0.4 mg if calculated against a rapid intravenous injection).