See also Hormonal contraceptives – emergency contraception ; Hormonal contraceptives—progestogen implants ; Hormonal contraceptives—progestogen injections General information Most aspects of progestogens are dealt with in the monograph on hormonal contraception. For a complete account of the adverse effects of progestogens, readers should consult the following monographs as well as this one: Hormonal contraceptives—intracervical and intravaginal Hormonal contraceptives—oral Hormonal contraceptives—progestogen implants Hormonal contraceptives—progestogen injections Hormone replacement therapy—estrogens…

General information Progabide acts, together with its metabolites, as an agonist at both GABA A and GABA B receptors. It has been used in the treatment of spasticity [ , ], epilepsy and movement disorders [ , ], and benign essential tremor [ ]. A high proportion of patients suffer from transient minor adverse reactions, such as drowsiness, nausea, weakness, or dizziness. You’re Reading a Preview…

See also Anticholinergic drugs General information Procyclidine is an anticholinergic drug [ ]. The usual oral dose, 20–30 mg/day, is likely to produce only mild anticholinergic adverse reactions, but involuntary movements, with chewing and sucking, have been described in some patients [ ]. Even small doses have produced toxic confusional states when procyclidine was combined with phenothiazines for schizophrenia. Procyclidine is more likely to produce sedation…

See also Neuroleptic drugs General information Prochlorperazine is a phenothiazine derivative. Organs and systems Cardiovascular There was an association between the use of antipsychotic drugs and the risk of venous thromboembolism in a large nested case-control study using the UK QResearch primary-care database [ ]. Cases (n = 25 532) with a first ever record of venous thromboembolism were matched with up to four controls (n…

See also Cytotoxic and immunosuppressant drugs General information Procarbazine is an alkylating agent that has been used in the treatment of Hodgkin’s disease in regimens such as MOPP (chlormethine (mechlorethamine), vincristine (Oncovin), procarbazine, and prednisolone) and BEACOPP (bleomycin, etoposide, doxorubicin (Adriamycin), cyclophosphamide, vincristine, procarbazine, and prednisone) [ ]. It is also used to treat glioblastoma multiforme. As with many cytotoxic and cytostatic drugs, it can be…

See also Anesthetics, local ; Chloroprocaine General information Procaine is an aminoester local anesthetic. It is most widely used as a component of procaine penicillin. 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 Acecainide General information Procainamide is a Class Ia antidysrhythmic drug with electrophysiological actions similar to those of quinidine [ ]. Adverse reactions to procainamide are predominantly on the heart. It causes reduced myocardial contractility and hypotension and prolongs the QT interval, with consequent dysrhythmias and conduction defects. The lupus-like syndrome most commonly causes polyarthralgia, myalgia, fever, and pleurisy. Neutropenia has been relatively commonly reported…

General information Probucol is a lipid-modifying drug that is stored in fat, from which it is slowly released; it can still be detected in plasma 6 months after the end of treatment. Adverse reactions to probucol have been reviewed [ ]. Drug studies Observational studies A series of 30 patients was given probucol for 60 days; adverse reactions were reported in five subjects, four of them…

See also Prebiotics General information Probiotics are organisms or mixtures of organisms that are used to colonize the gut, preventing colonization by pathogenic organisms. They include bifidobacteria, Escherichia coli Nissle 1917, and lactobacilli. Escherichia coli Nissle 1917 Escherichia coli Nissle 1917 is a non-pathogenic organism that has been used as a probiotic in a formulation called Mutaflor to treat inflammatory bowel disease [ ], irritable bowel…

General information Probenecid is a uricosuric agent. Soreness of the gums, gastrointestinal irritation, rashes, pyrexia, and the nephrotic syndrome have been reported [ ]. Probenecid can cause drug–drug interactions, because it is an inhibitor of the renal tubular secretion of acids and bases [ ]. Organs and systems Urinary tract Membranous nephropathy has been attributed to probenecid in a 79-year-old man who had taken probenecid 500…

See also Streptogramins General information Pristinamycin is a combination of streptogramin A (pristinamycin IIA) and streptogramin B (pristinamycin IB), derived from Streptomyces pristinaespiralis [ ]. The former is a polyunsaturated macrolactone and the latter is a peptidic macrolactone or depsipeptide. Group A and group B streptogramins are both bacteriostatic by reversible binding of the 50S subunit of 70S bacterial ribosomes. Together, however, they are synergistic and…

See also Antiepileptic drugs ; Phenobarbital General information Primidone, a deoxybarbiturate, is partly metabolized to phenobarbital, which is responsible for some of its pharmacological effects in epilepsy [ ]. It has also been used to treat essential tremor [ ]. There is also evidence that phenobarbital, when given in a high dose, can be converted to primidone [ ]. During chronic dosing, adverse reactions to primidone…

General information The 8-aminoquinolines were the first synthetic antimalarial drugs to be introduced into medicine. Pamaquine (Plasmochin) was the first to be marketed in 1926, but primaquine proved to have the highest chemotherapeutic index of the many compounds tested. Primaquine is rapidly absorbed, extensively distributed, and predominantly cleared by non-renal elimination. Its principal metabolite is carboxyprimaquine. While primaquine itself is rapidly eliminated from the plasma, the…

General information Prilocaine is an aminoamide local anesthetic. It can be used on its own, but it is also included in the formulation known as Emla, a eutectic combination of prilocaine with lidocaine (25 mg/ml each), which is used as a local anesthetic in topical administration for, for example, superficial surgery and venepuncture. Emla cream causes minor local adverse reactions, such as itch, burning, and localized…

General information Preservatives that are often found in cosmetics include formaldehyde, quaternium-15, imidazolidinyl urea, diazolidinyl urea, parabens mix, 5-chloro-2-methyl-4-isothiazolin-3-one + 2-methyl-4-isothiazolin-3-one (MCI/MI, Kathon CG), and methyldibromoglutaronitrile (MDBGN, Euxyl K400). Polyhexamethylenebiguanide, a biocide structurally related to hexamidine, is added to cosmetics as a preservative. You’re Reading a Preview Become a Clinical Tree membership for Full access and enjoy Unlimited articles Become membership If you are a member.…

See also Calcium channel blockers General information Prenylamine is a coronary vasodilator that depletes myocardial catecholamine stores and has some calcium-channel blocking activity. It has been used in the treatment of angina pectoris, but it often causes ventricular dysrhythmias and has been superseded by less toxic drugs. Organs and systems You’re Reading a Preview Become a Clinical Tree membership for Full access and enjoy Unlimited articles…

General information Prenalterol has dobutamine-like positive inotropic effects and has been used in severe heart failure [ ] and to treat overdosage with beta-blockers [ ] and amitriptyline [ , ]. 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 Antiepileptic drugs General information Like gabapentin, pregabalin (3-isobutyl GABA) binds to the alpha-2 delta subunit of voltage-gated calcium channels. It has been evaluated in patients with epilepsy, neuropathic pain of various sorts, including painful diabetic peripheral neuropathy, generalized anxiety disorder, fibromyalgia syndrome, and restless legs syndrome. The usual dosage regimen is 150–600 mg Pregabalin is eliminated unchanged by the kidneys. It does not induce…

See also Probiotics General information The concept of prebiotics, as originally stated [ ], was manipulation of the composition of the gut flora by encouraging the growth of endogenous gut organisms, as an alternative to probiotics (qv), such as Bifidobacterium and Lactobacillus , microbial food supplements that introduce organisms into the gut, with the intention of improving intestinal microbial balance. Prebiotics are non-digestible food ingredients that…

See also Alpha-adrenoceptor antagonists General information Prazosin is an alpha 1 -adrenoceptor antagonist. Its main uses are in the treatment of hypertension, congestive cardiac failure, Raynaud’s syndrome, and the symptoms of benign prostatic hyperplasia, but it has also been used in the management of post-traumatic stress disorder [ ]. Organs and systems Cardiovascular Postural hypotension and reflex tachycardia, particularly on standing, are features of the first-dose…