See also Opioid receptor agonists General information Pethidine (meperidine) is about one-tenth as potent as morphine in terms of analgesia. It is metabolized in the liver by hydrolysis and conjugation, either directly or via N-demethylation to norpethidine. Norpethidine (normeperidine) is significantly less analgesic, with a longer half-life (15–20 hours). Drug studies Observational studies Hypotension, hypoxemia, and pain-related agitation were adverse events reported after co-administration of pethidine…

See also Vaccines General information Note on abbreviations DT = Diphtheria + tetanus toxoids DTP = Diphtheria + tetanus toxoids + pertussis DTaP = Diphtheria + tetanus toxoids + acellular pertussis DTwP = Diphtheria + tetanus toxoids + whole cell pertussis Drug studies Acellular pertussis vaccine Whole-cell and acellular pertussis vaccines have been reviewed, with emphasis on the protectivity of the various virulence factors and antigens…

See also Neuroleptic drugs General information Perphenazine is a phenothiazine neuroleptic drug. 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

General information Benzoyl peroxide Benzoyl peroxide is an antimicrobial and keratolytic agent used in the treatment of acne; it is also added to some foods. It is a catalyst for cross-linking in the production of plastics and is occasionally used in acrylic resin systems (for example composite dental fillings, dental prostheses), in which it is formed during the cross-linking process. It is also a component of…

See also Angiotensin-converting enzyme inhibitors General information Perindopril is a prodrug ester of perindoprilat, an angiotensin converting enzyme (ACE) inhibitor that has been used in patients with hypertension and heart failure. An updated review of its use in hypertension has appeared [ ]. Drug studies Observational studies A large French open postmarketing study in 47 351 hypertensive patients treated with perindopril for 12 months did not…

General information Perhexiline, 2-(2,2-dicyclohexylethyl)piperidine, was originally developed as an antianginal drug in the late 1960s [ ]. However, it caused severe serious adverse reactions, particularly a peripheral neuropathy and hepatotoxicity, in a small proportion of patients, particularly poor CYP2D6 metabolizers, and its use declined. Although it was withdrawn in some countries, it has continued to be used elsewhere, for example as a last-line drug for refractory…

General information Pergolide is a dopamine receptor agonist, who adverse effects and reactions resemble those of bromocriptine [ ]. Drug studies Observational studies In 41 patients with Parkinson’s disease who took pergolide, confusion and hallucinations were the adverse reactions that were most likely to result in withdrawal of pergolide [ ]. Symptoms suggestive of dose-related angina pectoris occurred in four patients in the open phase and…

See also Hemoglobin-based oxygen-carrying blood substitutes; Ultrasound contrast agents General information Oxygen carriers can be divided into two classes: synthetic perfluorocarbons and hemoglobin-based oxygen carriers, prepared from hemoglobin of human or bovine origin (see separate monograph). It is important for the laboratory medicine community to be aware of their effects on routine laboratory testing and the settings in which they might be used [ ]. The…

General information Pentoxifylline (oxipentifylline) is a methylxanthine that antagonizes the vasoconstrictor effects of catecholamines and increases cyclic AMP concentrations, causing smooth muscle to relax. It has also been claimed to correct impaired microcirculation, by improving various factors that disturb blood rheology, and to reduce the generation of toxic free radicals from leukocytes during ischemic leg exercise in patients with intermittent claudication. Pentoxifylline has been used to…

General information Pentostatin (2′-deoxycoformycin) is a natural product isolated from Streptomyces antibioticus . It is a potent and irreversible inhibitor of adenosine deaminase, which is widely distributed in mammalian tissues, with particularly high constitutive activity in lymphocytes (T cells more than B cells). Pentostatin-related inhibition of adenosine deaminase results in accumulation of deoxyadenosine and its nucleotides, which in turn results in a negative regulatory effect on…

General information Pentetrazol (pentylenetetrazol) is a central and respiratory stimulant, similar to doxapram hydrochloride. It is a GABA A receptor antagonist and is anxiogenic [ ]. It has been used in respiratory depression and has also been included in multi-ingredient formulations for respiratory tract disorders, including cough, and for the treatment of hypotension and pruritus. However, the general consensus is that pentetrazol does not have a…

General information Pentazocine is a partial agonist at opioid receptors. Adverse reactions to effective doses are largely typical of its class [ , ], with some quantitative exceptions. Drug studies Comparative studies Pentazocine and morphine were compared in 16 non-abusing volunteers recruited via posters and local newspaper advertisements [ ]. Pentazocine had dose-related effects on subjective, psychomotor, and physiological variables, and the clinically relevant dose of…

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General information Pentamorphone (14β-pentylaminomorphinone) was developed as a potent opiate with a rapid onset and short duration of action, similar to that of fentanyl, which was reported to produce analgesia with limited depression of ventilation [ ]. However, it proved to be ineffective in the treatment of acute pain after major abdominal or orthopedic surgery in a double-blind, randomized, placebo-controlled study of 72 patients who were…

General information Pentamidine, an aromatic diamine, has been known since the late 1930s as a treatment for trypanosomiasis and some forms of leishmaniasis. In recent times it has been extensively used in the treatment of Pneumocystis jirovecii pneumonia. Its mechanism of action is probably related to inhibition of dihydrofolate reductase and inhibition of oxidative phosphorylation and nucleic acid synthesis, as well as an effect on aerobic…

General information Pentagastrin is a short peptide that stimulates the production of gastric acid from the stomach by a direct action on gastrin receptors and of calcitonin from thyroid C cells [ ]. It also acts on cholecystokinin receptors centrally and stimulates the release of adrenocorticotropin (ACTH) and hence the production of glucocorticoids [ ]. Pentagastrin was originally used to test for suppression of gastric acid…

See also Beta-lactam antibiotics General information The basic structure of the penicillins consists of a thiazolidine ring, the beta-lactam ring, and a side chain. The beta-lactam ring is essential for antibacterial activity. The side chain determines in large part the antibacterial spectrum and pharmacological properties of a particular penicillin. The rapid emergence of bacteria, particularly Staphylococcus aureus , that produce beta-lactamases (penicillinase) has been partly countered…

General information Penicillamine is dimethylcysteine or 2-amino-3-mercapto-3-methylbutyric acid, a sulfur-containing amino acid. It has three functional groups that largely determine its pharmacological effects: an alpha-amine, a carboxyl, and a sulfhydryl group. Because the levorotatory isomer, l -penicillamine, is a pyridoxine antagonist and toxic, purified d -penicillamine is used for medicinal purposes instead of the racemic mixture. Here “penicillamine” refers to the d -isomer unless otherwise specified.…

General information Pemoline has similar pharmacological actions to dexamfetamine and methylphenidate, and was used in the management of hyperactivity disorders in children. However, the evidence linking pemoline to life-threatening liver failure prompted the Food and Drugs Administration to require the manufacturer to add a black box warning to the package insert, and in the UK the Committee on Safety of Medicines withdrew marketing approval for pemoline,…

General information Pemirolast is a mast-cell stabilizer, like cromoglicate, used in eye-drops for the treatment of allergic disorders [ ]. It has also been used to prevent coronary artery restenosis after the insertion of a stent [ ]. 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