Remifentanil

See also Opioid receptor agonists General information Remifentanil is a pure μ opioid (OP 3 , MOR) receptor agonist with a very short duration of action. It therefore has to be given by continuous intravenous infusion and is used as a supplement to general anesthesia during induction and as an analgesic during maintenance of anesthesia. It causes the same adverse reactions as other opioid agonists: respiratory…

Remacemide

General information Remacemide hydrochloride is a low-affinity, non-competitive N-methyl- d -aspartate (NMDA) receptor blocker that has been used in epilepsy, Parkinson's disease, Huntington's chorea [ ], and neuroprotection after stroke [ ]. Its pharmacology, clinical pharmacology, uses, and adverse reactions and interactions have been reviewed [ , ]. However, there appear to be no current clinical studies of this drug and there have been no publications…

Reboxetine

General information Reboxetine is a selective noradrenaline re-uptake inhibitor with low affinity for α-adrenoceptors and muscarinic receptors [ ]. In controlled trials the following adverse events occurred significantly more often with reboxetine than with placebo: dry mouth (27%), constipation (17%), increased sweating (14%), insomnia (14%), urinary hesitancy (5%), impotence (5%), tachycardia (5%), and vertigo (2%) [ ]. Organs and systems Endocrine Pseudopheochromocytoma has been attributed to…

Razaxaban

General information Razaxaban, a selective oral direct factor Xa inhibitor [ , ], was discontinued by the manufacturer after the three higher doses in a dose-ranging study in venous thromboembolism caused an increased risk of bleeding. 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

Ravuconazole

See also Antifungal azoles [for systemic use] General information Ravuconazole is an antifungal azole, similar in structure to fluconazole. It has a long half-life suitable for once-daily dosing. 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

Rasburicase

General information Rasburicase is recombinant urate oxidase, which causes the breakdown of uric acid to 5-hydroxyisourate, which is further broken down to allantoin. Although there is a gene for urate oxidase in human, it is non-functional, and purine catabolism therefore ends with uric acid. This may be advantageous, because uric acid is an antioxidant. In the root nodules of legumes urate oxidase is necessary for nitrogen…

Rasagiline

General information Rasagiline is a propargylamine that irreversibly and selectively inhibits monoamine oxidase type B and is 5–10 times more potent than selegiline. Its pharmacology, clinical pharmacology, clinical efficacy, and adverse reactions have been reviewed [ , ]. Rasagiline is rapidly absorbed from the gastrointestinal tract and readily enters the brain. Unlike selegiline, which is metabolized to amphetamines, rasagiline is metabolized to the non-amphetamine compound aminoindan.…

Rapacuronium

General information Rapacuronium, an aminosteroid non-depolarizing neuromuscular blocking agent with a rapid onset and a comparatively short duration of action [ , ], was withdrawn from the US market in March 2001 and subsequently worldwide. The manufacturers informed the FDA in an open letter about postmarketing reports of severe bronchospasm and some deaths of unknown origin associated with rapacuronium. The severity of the incidents recently reported…

Ranunculaceae

General information The genera in the family of Ranunculaceae ( Table 1 ) include anemone, buttercup, columbine, hellebore, larkspur, marsh marigold, and pasque flower. Table 1 Genera of Ranunculaceae Aconitum (monkshood) Clematis (leather flower) Kumlienia (false buttercup) Actaea (baneberry) Consolida (knight’s-spur) Myosurus (mousetail) Adonis (pheasant’s eye) Coptis (gold thread) Nigella (nigella) Anemone (anemone) Delphinium (larkspur) Pulsatilla (pasque flower) Aquilegia (columbine) Enemion (false rue anemone) Ranunculus (buttercup)…

Ranolazine

General information Ranolazine is a piperazine derivative approved for the treatment of chronic angina [ ]. It is thought to act by shifting myocardial energy metabolism away from free fatty acids and towards glucose as a substrate for production of adenosine triphosphate. It also has antidysrhythmic actions [ ]. Ranolazine is metabolized in the small intestine and liver to active metabolites, primarily by CYP3A4 and CYP3A5…

Ranitidine

See also Histamine H 2 receptor antagonists General information Ranitidine is a histamine H 2 receptor antagonist. Compared with cimetidine, it inhibits hepatic metabolism of other substances only to a very slight extent and is not antiandrogenic. In most other respects it is similar to cimetidine. Drug studies Comparative studies Effervescent ranitidine 150 mg bd has been compared with as-needed calcium carbonate antacids 750 mg in…

Ranibizumab

Ranibizumab is a specific, affinity-mature, recombinant, humanized, antivascular endothelial growth factor-A (anti-VEGF-A) antibody fragment, which binds all isoforms of VEGF-A, rendering them inactive; it is effective in the treatment of age-related macular degeneration after intravitreal injection [ ]. Drug studies Comparative studies In a phase I/II randomized controlled trial 64 patients received either ranibizumab 0.3 or 0.5 mg (n = 53) or usual care (n =…

Ramoplanin

General information Ramoplanin was the first in a new class of antimicrobials to reach clinical trials [ ]. It is a glycolipodepsipeptide produced by the fermentation of Actinoplanes species [ ]. Ramoplanin blocks bacterial cell wall biosynthesis by interfering with peptidoglycan production. It inhibits the N-acetylglucosaminyltransferase-catalysed conversion of lipid intermediate I to lipid intermediate II, a step that occurs before the transglycosylation and transpeptidation reactions. Unlike…

Ramipril

See also Angiotensin-converting enzyme inhibitors General information Ramipril is an ACE inhibitor, a prodrug that is rapidly hydrolysed after absorption to its active metabolite ramiprilat. It has been used in patients with hypertension, heart failure, and myocardial infraction. Organs and systems Metabolism Hypoglycemia has been attributed to several drugs in a complicated sequence of effects [ ]. A 64-year-old man with type II diabetes, hypertension, and…

Raltitrexed

See also Cytotoxic and immunosuppressant drugs General information Raltitrexed is a specific inhibitor of thymidylate synthase. It is used to treat colorectal cancers. In about 1000 patients with advanced colorectal cancer, the dose-limiting toxic effects in phase 1 studies were gastrointestinal toxicity, myelosuppression, and weakness; adverse events during phase 2 and 3 studies were similar to those seen during phase 1 [ ]. In all comparative…

Raloxifene

General information Raloxifene is a non-steroidal so-called “selective estrogen receptor modulator” (SERM), that is it binds to estrogen receptors, but this binding produces agonist effects at some sites and antagonist effects at others [ ]. It has estrogen agonist effects on bone and lipid metabolism but estrogen antagonist effects on the breast and endometrium; it is also claimed by its protagonists to have cardioprotective effects, perhaps…

Radiopharmaceuticals

See also Thorotrast General information Radioactive substances may be used in medicine as tracers, the quantities used in this case being merely sufficient to enable them to be detected, or as therapeutic agents, in which case the quantities employed and the amount of radiation emitted may be considerable. Risks resulting from the radiation itself fall outside the scope of this volume. Radio-iodine is covered in a…

Radioactive iodine

General information Three radioactive isotopes of iodine are currently used in clinical medicine: 1. 131 I has a radioactive half-life of 8 days and a high-energy emitter; it is used mainly in the therapy of hyperthyroidism and thyroid cancer. 2. 123 I has a radioactive half-life of 13 hours and has replaced 131 I for diagnostic purposes; however, for in vivo imaging meta-stable technetium-99 ( 99m…

Racecadotril

General information Racecadotril (ecadotril, anorphan, (S)-aetophan), through its active metabolite thiorphan, is an inhibitor of the neutral endopeptidase known as enkephalinase, thereby increasing exposure to substrates of the enzyme, including enkephalins and atrial natriuretic peptide [ ]. Increased exposure to atrial natriuretic peptide has not proved beneficial in patients with cardiac failure [ ]. However, the antihypersecretory effect in the gut makes it useful in the…

Rabies vaccine

See also Vaccines General information Rabies vaccine was for a long time prepared from infected brain tissue, and neurological complications were likely to occur in as many as one in 300 cases. A second-generation vaccine prepared from duck embryo tissue is better tolerated in this respect, and third-generation vaccines prepared in non-neural tissue cultures or in human diploid cell (HDC) vaccines with a progressive improvement in…