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Biomedical subjects

B Ameer

Publications and source records attributed to B Ameer.

28 records · Page 2Linked to original sources

Age does not alter acetaminophen absorption.

Twenty-eight healthy volunteers (age range, 22-78 years) received 650 mg of acetaminophen (AAP) on three separate occasions. The modes of administration were 1) intravenous, 5-minute infusion; 2) oral, with two 325-mg tablets; and 3) oral, with 650 mg as an elixir preparation. Plasma levels of AAP were determined in blood samples drawn up to 12 hours after the dose. The mean (+/- sd) kinetic variables for absorption of AAP from tablets in young and elderly were peak plasma concentration, 11.8 (+/- 4.2) vs 10.9 (+/- 4.1) micrograms/ml; peak time, 0.79 (+/- .54) vs 0.69 (+/- .40) hours after the dose; absorption half-life, 12.6 (+/- 9.8) vs. 8.2 (+/- 5.3) minutes; and absolute systemic availability, 79 (+/- 9) vs 72 (+/- 11) per cent. For AAP elixir, the corresponding values were 12.6 (+/- 5.4) vs 13.7 (+/- 6.0) micrograms/ml; 0.52 (+/- .24) vs 0.54 (+/- .51) hours; 8.6 (+/- 6.2) vs 6.1 (+/- 6.6) minutes; and 87 (+/- 9) vs 80 (+/- 9) per cent. Absolute bioavailability of both oral dosage forms was significantly less then 100 per cent in all groups. Elderly subjects tended to show lower availability of both oral preparations, but the difference was of borderline significance (P less than .50). Age did not influence any other measures of absorption. Since the absorption rate of acetaminophen may be indicative of the gastric emptying rate, age does not appear to alter this rate-limiting step in drug absorption.

Acetaminophen↗

Increased metabolic clearance of acetaminophen with oral contraceptive use.

The effect of chronic low-dose oral contraceptive steroid use on the pharmacokinetics of intravenous acetaminophen was determined. Eight women using low-dose (under 50 micrograms) estrogen oral contraceptive steroid for more than 3 months were matched for age and weight (mean age, 25.9 years; mean weight, 58.3 kg) with 8 female controls not using the steroid (mean age, 26.0 years; mean weight, 55.5 kg). No subject was taking other drugs. Oral contraceptive steroid subjects had a lower elimination half-life of acetaminophen (2.12 hours) than controls (2.71 hours) (P less than .005). Volume of distribution was similar for both groups (oral contraceptive group, 1.04 liters/kg; controls, 0.96 liters/kg; NS). Total metabolic clearance was significantly higher in oral contraceptive subjects (5.81 ml/min/kg, versus 4.12 ml/min/kg for controls; P less than .02). As volume of distribution and body weight are similar for both groups, the decrease in acetaminophen elimination half-life among contraceptive steroid users is the result of increased total metabolic clearance. Thus, low-dose estrogen oral contraceptive steroid may stimulate the metabolism of a conjugatively metabolized drug such as acetaminophen, in contrast to contraceptive steroid impairment of the clearance of some oxidatively metabolized drugs, with antipyrine being the prototype.

Acetaminophen↗

Drug therapy reviews: evaluation of butorphanol tartrate.

The chemistry, pharmacology, uses, side effects, pharmacokinetics and dosage of butorphanol tartrate, a narcotic analgesic with antagonist properties, are reviewed. When administered intramuscularly or intravenously, butorphanol tartrate appears to be as effective for relieving moderate to severe pain as are pentazocine, meperidine and morphine. Butorphanol produces sedation more commonly and, at therapeutic dosages, depresses respiration as much as these other narcotic analgesics. A limited number of long-term clinical studies suggest a lower physical dependence liability with butorphanol than with other narcotic analgesics. Butorphanol is more expensive than morphine and, for most patients, offers no significant advantages over morphine for short-term use. Because butorphanol's cardiovascular effects are not completely understood, morphine also remains the drug of choice for pain associated with myocardial infarction.

Butorphanol↗

Acetaminophen.

Acetaminophen is an effective mild analgesic and antipyretic agent. In double-blind, controlled experimental pain studies of short duration, acetaminophen is superior to placebo and produces analgesia comparable to that produced by aspirin. The frequency of adverse reactions to therapeutic doses of acetaminophen is low, as is that of aspirin. Overdosage with acetaminophen, however, may result in irreversible hepatotoxicity. Since clinical manifestations of intoxication can be of slow onset, physicians may tend to delay initiation of definitive therapy. Intravenous cysteamine, and possibly oral methionine, appear to be effective in preventing hepatotoxicity if they are administered with 10 h of drug ingestion. Physicians should be aware of the potential danger of acetaminophen overdosage and alerted to its clinical manifestations.

Acetaminophen↗

Inservice pharmacy technician training program.

The development and implementation of a two-month inservice training program for hospital pharmacy supportive personnel is discussed. A task-oriented approach was used to define the instructional objectives of the program. To emphasize the job-related nature of the instruction, conferences and workshops were selected as the primary teaching methods. A specific instructional plan was designed for drug conferences, giving the trainee an active role in the learning of drug names and dosage forms. On-the-job experience, comprising 30% of the training time, gradually was incorporated into the program. Staff pharmacists and supervisors assumed the teaching responsibilities. During weekly evaluation sessions with each trainee, the coodinator discussed the trainee's performance, pin-pointed deficiencies and suggested means of improvement. The benefits of the program, in terms of selection and sequence of instructional programs, student assessment and program evaluation, are discussed.

Curriculum↗

Effect of food on acetaminophen absorption in young and elderly subjects.

Twenty-four healthy volunteers aged 22 to 78 years received 650-mg doses of acetaminophen (AAP) on five separate occasions. The modes of administration were: intravenous AAP by 5-minute infusion; oral AAP as two 325-mg tablets in the fasting state; oral AAP 650 mg as an elixir preparation in the fasting state; tablets with food; and elixir with food. Plasma concentrations of AAP were determined by high-pressure liquid chromatography for up to 12 hours after the dose. In both the young and the elderly groups, the four oral modes of administration were significantly different with respect to peak plasma concentration (P less than 0.001), time to peak plasma concentration (P less than 0.001), and systemic availability (P less than 0.01). Although food slowed the rate of absorption of both oral preparations, no significant difference in peak acetaminophen plasma concentration or time of peak concentration was observed as a function of age. Absolute systemic availability of elixir and tablets in the fasting state tended to be lower in the elderly subjects (P less than 0.05). However, when either preparation was coadministered with food, there were no differences between the two age groups. Thus, age as such does not appear to be a critical determinant in the design of oral acetaminophen dosage schedules.

Absorption↗

Effect of food on ethambutol absorption.

The effect of food on the absorption of ethambutol hydrochloride tablets was investigated. Following an overnight fast, 11 normal volunteers ingested ethambutol hydrochloride tablets (15 mg/kg dosage) once while fasting and once immediately following a standardized breakfast. The sequence of administration was assigned randomly. Food and fasting trials were at least seven days apart. In both trials, blood samples were drawn at 1, 2, 3, 4, 6, 8, 12, and 24 hours after dosing. Ethambutol concentrations in plasma were determined by a gas-chromatography method. Completeness of absorption was assessed by calculation of the area under the 24-hour plasma concentration curve (AUC) for each subject after each mode of administration using a trapezoidal approximation. Within-subject difference in AUC between food and fasting conditions was evaluated using the Student's t test for paired data. There was no significant difference between the mean AUC-fasting and the mean AUC-food (p greater than 0.05). Food does not appear to influence the extent of ethambutol absorption.

Ethambutol↗