See also Angiotensin-converting enzyme inhibitors General information The pharmacology, therapeutic uses, and safety of the ACE inhibitor quinapril have been reviewed [ ]. Organs and systems You’re Reading a Preview Become a Clinical Tree membership for Full access and enjoy Unlimited articles Become membership If you are a member. Log in here

General information Quinagolide is a non-ergot benzoquinoline dopamine D 2 receptor agonist. It has mainly been used to treat hyperprolactinemia [ , ], and also in Parkinson’s disease [ ], ovarian hyperstimulation syndrome [ ], and to suppress lactation [ ]. Reported adverse reactions include gastrointestinal upsets, anorexia, weight loss, and episodes of fainting [ ]. You’re Reading a Preview Become a Clinical Tree membership for…

General information The pharmacology, efficacy, and safety of quetiapine, an atypical neuroleptic drug, have been extensively reviewed [ ]. Quetiapine interacts with a broad range of neurotransmitter receptors and has a higher affinity for serotonin 5HT 2A receptors than dopamine D 2 receptors in the brain. A violation by AstraZeneca, consisting of oral and written promotion of quetiapine for major depressive disorder, an unapproved use, has…

See also Benzodiazepines General information Quazepam is a long-acting benzodiazepine with effects similar to those of diazepam. Organs and systems Nervous system The hangover effects of night-time administration of triazolam 0.25 mg, flunitrazepam 1 mg, and quazepam 15 mg were compared in 15 healthy subjects, who were given one of the three hypnotics at each session in a single-blind, crossover study [ ]. There were no…

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General information Pyrrolizidine alkaloids occur in a large number of plants, notably the genera Crotalaria (Fabaceae), Cynoglossum (Boraginaceae), Eupatorium (Asteraceae), Heliotropium (Boraginaceae), Petasites (Asteraceae), Senecio (Asteraceae), and Symphytum (Boraginaceae) ( Table 1 ) [ ]. Table 1 Pyrrolizidine alkaloids in various genera Genus Pyrrolizidine alkaloids Crotalaria albida Croalbidine Crotalaria anagyroides Anacrotine, methylpyrrolizidine Crotalaria aridicola Various dehydropyrrolizidines Crotalaria axillaris Axillaridine, axillarine Crotalaria barbata Crobarbatine Crotalaria burha Croburhine,…

General information Pyritinol (pyridoxine disulfide or pyrithioxine) is a sulfhydryl-containing compound, a dimer of 5-thiopyridoxine. It was used from 1961 onwards as a psychostimulant of doubtful efficacy, but apparently without adverse reactions, and then largely abandoned. When it was re-introduced in some countries for rheumatoid arthritis, adverse reactions were registered in 25% of patients. Cross-allergy with d -penicillamine has been hypothesized to explain the apparently higher…

General information Pyrimethamine is the most active antimalarial of the 2–4-diaminopyrimidines, its effect being due to inhibition of the conversion of folic acid to its active form, folinic acid. It is also effective in toxoplasmosis. Its antiprotozoal and antimalarial activity is enhanced by the addition of sulfonamides. Pyrimethamine is well absorbed in healthy subjects; the half-life is 80–95 hours [ ]. Absorption after intramuscular injection is…

See also Vitamins General information Pyridoxine (vitamin B 6 ) requirements vary with protein intake: the daily Average Requirement is 13 micrograms/g protein intake and the Population Reference Intake is 15 micrograms/g protein intake. In adults this translates into a daily Average Requirement of 1.3 mg/day for men and 1.0 mg/day for women, and a Population Reference Intake of 1.5 mg/day for men and 1.1 mg/day…

See also Antituberculosis drugs General information Pyrazinamide is a pyrazine analogue of nicotinamide. It is bactericidal for Mycobacterium tuberculosis in an acid environment and in macrophages [ ]. Pyrazinamide passively diffuses into Mycobacterium tuberculosis , where pyrazinamidase (nicotinamidase) converts it to the active form pyrazinoic acid, which slowly leaves out of the cell at acid pH via a weak efflux pump and is protonated; the protonated…

General information Pyrantel is an antihelminthic drug that is effective against intestinal nematodes, including roundworms ( Ascaris lumbricoides ), threadworms ( Enterobius vermicularis ), Trichostrongylus species, and the tissue nematode Trichinella spiralis . Although it is effective against hookworms, it is less effective against Necator americanus than against Ancylostoma duodenale . Pyrantel is usually given as the embonate or pamoate in a single dose of 10…

General information In 1957, psilocybin was isolated from the Psilocybe mexicana mushroom and it has since been identified as a component of over 75 distinct mushroom species [ ]. Psilocybin-containing mushrooms, also called “magic mushrooms”, are used recreationally, with an expanding worldwide distribution. They are sold in “smart shops” and over the internet. Psilocybin is also used in nightclubs, although its use is not as popular…

See also Xanthines General information Proxyphylline is a theophylline derivative used as a bronchodilator. It is readily absorbed from the gastrointestinal tract and is not converted to theophylline. Drug studies You’re Reading a Preview Become a Clinical Tree membership for Full access and enjoy Unlimited articles Become membership If you are a member. Log in here

See also Anesthetics, local General information Proxymetacaine (rINN) is a local anesthetic, an ester of meta-aminobenzoic acid. It is often used in ophthalmology. It is also known as proparacaine (USAN). Organs and systems You’re Reading a Preview Become a Clinical Tree membership for Full access and enjoy Unlimited articles Become membership If you are a member. Log in here

See also Individual agents General information Proton pump inhibitors inhibit the H + /K + -ATPase (proton pump) in oxyntic cells of the stomach, the final common pathway in the secretion of gastric acid in response to a variety of stimuli, such as gastrin and histamine. Their use in acid-related disorders has been extensively reviewed [ ]. General adverse effects and adverse reactions The adverse reactions…

General information Protirelin is a synthetic tripeptide that stimulates the hypophyseal secretion of thyrotrophin (thyroid-stimulating hormone, TSH). It is used mainly for diagnostic purposes in dynamic tests of pituitary and hypothalamic function, but its use in the assessment of hyperthyroidism has been superseded by sensitive assays of thyrotrophin [ ]. Protirelin has neurotransmitter properties and has been used to treat a variety of neurological disorders, including…

See also Coagulation proteins ; Drotrecogin General information Prothrombin complex products contain constant amounts of clotting factors II, VII, IX, and X, bypassing the need for factor VIII in the clotting cascade. They are used to reverse the effects of oral anticoagulants (for example during surgery or bleeding episodes) [ ] and to treat bleeding episodes in hemophiliacs with inhibitors of factor VIII [ ]. Prothrombin…

General information In addition to their natural occurrence, for example in cow’s milk, protein hydrolysates are added to hair-care products, such as shampoos and conditioners, and are supposed to “repair” damaged hair. Hydrolysed proteins are also used in other body-care products, for example soaps, bath gels, and creams. They are also used in sports drinks, which contain mostly dipeptides and tripeptides [ ]. You’re Reading a…

General information Protamine, derived from salmon sperm, combines with and neutralizes heparin through an acid–base interaction. It is used to treat heparin toxicity but more commonly to reverse the effects of heparin after cardiopulmonary bypass. It is most commonly used as the sulfate, but chloride and hydrochloride salts are also occasionally used. Protamine has been used to produce a derivative of insulin, which is relatively insoluble,…

General information Eicosanoids are the oxygenated metabolites of 20-carbon unsaturated fatty acids found in the phospholipids of cell membranes (Greek eikosi = 20). The eicosanoids include the prostaglandins, thromboxanes, and leukotrienes. Precursor fatty acids include arachidonic acid C20:4n − 6 (for 2-series prostaglandins and thromboxane and 4-series leukotrienes), dihomogammalinolenic acid C20:3n − 6 (for PGE 1 ), and eicosapentaenoic acid C20:5n − 3 (for 3-series prostaglandins…