Pheniramine

See also Antihistamines General information Pheniramine is a first-generation antihistamine. 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

Phenindamine

See also Antihistamines General information Phenindamine is an antihistamine that is reputed to cause stimulation rather than sedation in some patients. However, in one small study the central nervous system effects of phenindamine were intermediate between those of terfenadine and diphenhydramine [ ]. You’re Reading a Preview Become a Clinical Tree membership for Full access and enjoy Unlimited articles Become membership If you are a member.…

Phenelzine

See also Monoamine oxidase inhibitors General information Phenelzine is a non-selective monoamine oxidase (MAO) inhibitor. Organs and systems Nervous system A potential risk of using a non-selective inhibitor in patients with Parkinson’s disease is illustrated by separate reports of the appearance of parkinsonism in patients taking phenelzine [ , ]. Speech blockage, so called, has been reported in a 34-year-old woman who had taken phenelzine 45…

Phencyclidine

General information Phencyclidine or 1-(1-phenylcyclohexy-1) piperidine (known as PCP, “angel dust”, and many other names) was originally developed as an anesthetic, but was abused as an illicit drug from the late 1960s onwards. It is a dopamine receptor agonist and an antagonist at the N-methyl- d -aspartate (NMDA) subtype of glutamate receptors. It has anticholinergic properties through blockade of ion channels in acetylcholine receptors. It has…

Phenazopyridine

General information Phenazopyridine, an azo dye, is used as a urinary tract analgesic. Although its use is not justified, because of toxicity, and although it was, for example, withdrawn in Greece in 1984, it continues to be used [ , ], and is available over the counter in some countries, for example the USA [ , ]. Organs and systems Nervous system Aseptic meningitis was diagnosed…

Phenazone (antipyrine)

General information Phenazone, commonly known as antipyrine, is still used therapeutically in some countries, although it is now used mainly as a marker of hepatic enzyme drug metabolizing activity. It is usually taken in combination with other analgesics, making attributability of adverse reactions difficult. Allergic reactions are rare [ , ]. Dichloralphenazone is a hypnotic composed of a complex of phenazone and chloral hydrate, which dissociates…

Pethidine (meperidine)

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…

Pertussis vaccines

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…

Perphenazine

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

Peroxides

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…

Perindopril

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…

Perhexiline

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…

Pergolide

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…

Perfluorocarbons

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…

Pentoxifylline

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…

Pentostatin

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…

Pentetrazol

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…

Pentazocine

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…

Pentamorphone

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…