See also Proton pump inhibitors General information The benefit to harm balance of rabeprazole, a proton pump inhibitor, has been reviewed [ , ]. The overall rate of drug withdrawal because of adverse reactions was 3%. Common adverse reactions included diarrhea, headache, and rashes. General adverse effects and adverse reactions In short-term and long-term studies of up to 2 years, headache was the most important reported…

General information Quinupristin and dalfopristin are two semisynthetic pristinamycin derivatives that are given in combination parenterally. Each component has bacteriostatic activity against Gram-positive bacteria, including multidrug resistant bacilli [ , ]. Quinupristin + dalfopristin can be used to treat macrolide-resistant streptococci, staphylococcal infections after failure of conventional therapy, or vancomycin-resistant Enterococcus faecium (and probably Enterococcus raffinosus ), but not vancomycin-resistant Enterococcus faecalis , Enterococcus avium ,…

General information Quinine was originally extracted from the bark of the Cinchona tree (Peruvian bark or Jesuits’ bark) and was used to treat ague (i.e. fever), usually due to malaria. It fell out of fashion with the advent of other antimalarial drugs, but has once again become the drug of first choice for malaria originating in areas with multiresistant Plasmodium falciparum . To be effective, quinine…

General information Quinidine is a class I antidysrhythmic drug. Its actions, clinical use, interactions, and adverse effects and reactions have been reviewed [ ]. General adverse effects and adverse reactions Gastrointestinal symptoms, including anorexia, nausea, and vomiting, are common. Quinidine has a negative inotropic effect on the heart and can cause heart failure and hypotension. It prolongs the QRS complex and QT interval and can cause…

General information Quinfamide is a dichloroacetyl quinolol that has been used as an amebicide [ ]. It acts on the trophozoites of Entamoeba histolytica , making the trophozoite incapable of propagation. It is not active against amebic cysts. In doses of 100–1200 mg adverse reactions have been frequent but mild, mainly comprising headaches and nausea [ ]. You’re Reading a Preview Become a Clinical Tree membership…

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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