Clin Pharmacokinet
-
Patients with renal insufficiency commonly require the administration of an opioid analgesic to provide adequate pain relief. The handling of morphine, pethidine (meperidine) and dextropropoxyphene in patients with renal insufficiency is complicated by the potential accumulation of metabolites. ⋯ Case reports of prolonged narcosis associated with the use of both codeine and dihydrocodeine in patients with renal insufficiency call for care to be used when prescribing these agents under such conditions. Although the pharmacokinetics of buprenorphine, alfentanil, sufentanil and remifentanil change little in patients with renal failure, the continuous administration of fentanyl can lead to prolonged sedation.
-
Sedation is currently administered to neonates experiencing pain and stress during intensive care for medical diseases, as well as postoperatively. Drugs commonly used for sedation in neonates include benzodiazepines (midazolam and lorazepam), chloral hydrate and opioids (fentanyl and morphine). Sedation protocols and dosage schedules are, in most cases, adapted from those which have been developed in children and even adults. ⋯ Alfentanil and sufentanil need further investigations to define their pharmacokinetic-pharmacodynamic properties in neonates. Although the choice of drug is important, the way the drug is used and monitored is equally important. All the drugs used for the sedation of neonates have large inter- and intraindividual differences in disposition, justifying specific pharmacological knowledge and individual dosage adjustments based on clinical evaluation of the patient and the monitoring of drug concentrations.
-
The recently introduced antidepressants, the selective serotonin reuptake inhibitors (SSRIs) [citalopram, fluoxetine, fluvoxamine, paroxetine and sertraline], are known for their clinical efficacy, good tolerability and relative safety. They differ from each other in chemical structure, metabolism and pharmacokinetic properties. Therapeutic drug monitoring of these compounds is not widely used, as the plasma concentration ranges within which clinical response with minimal adverse effects appears to be optimal are not clearly defined. ⋯ Due to its potent CYP2D6 inhibiting properties, comedication with this SSRI can lead to an increase of tricyclic antidepressants in plasma, as shown with amitriptyline and trimipramine. CYP3A has been claimed to be involved in the biotransformation of sertraline to norsertraline. Clinical investigations (with desipramine) confirmed in vitro findings that CYP2D6 inhibition by sertraline is only moderate. (ABSTRACT TRUNCATED)