Pharmacology
Browse 61 topics in pharmacology.
Alfentanil and Sufentanil Pharmacology
Alfentanil and sufentanil are synthetic 4-anilidopiperidine opioid agonists derived from fentanyl, sharing its characteristic phenylpiperidine structure but with distinct pharmacokinetic profiles that determine their...
Atracurium and Cisatracurium: Pharmacology
Atracurium is a benzylisoquinolinium non-depolarizing neuromuscular blocker with unique Hofmann elimination (chemical degradation at physiological pH and temperature) and ester hydrolysis by plasma cholinesterases....
Atracurium Pharmacology
Atracurium besylate is an intermediate-acting, non-depolarizing benzylisoquinolinium neuromuscular blocking agent (NMBA) characterised by organ-independent elimination through Hofmann elimination (spontaneous chemical...
Atropine Pharmacology
Atropine is a naturally occurring tropane alkaloid and the prototypical competitive muscarinic acetylcholine receptor antagonist. As a tertiary amine with a pKa of 9.7, it crosses the blood-brain barrier and produces...
Beta-Blockers Pharmacology
Beta-adrenergic receptor antagonists (beta-blockers) competitively inhibit catecholamine binding at beta-adrenoceptors, producing negative chronotropy (reduced heart rate), negative inotropy (reduced contractility),...
Bupivacaine
Bupivacaine is a potent, long-acting amide local anaesthetic widely used for neuraxial blocks (epidural, spinal), peripheral nerve blocks, and labour analgesia. Structure: Amide local anaesthetic (pipecoloxylidide),...
Calcium Channel Blockers Pharmacology
Calcium channel blockers (CCBs) inhibit voltage-gated L-type calcium channels, reducing calcium influx into cardiac and vascular smooth muscle cells. Classification is based on chemical structure : dihydropyridines...
Clonidine Pharmacology
Clonidine is a selective alpha-2 (α2) adrenergic receptor agonist with central sympatholytic, sedative, and analgesic properties that make it valuable in perioperative medicine. It is an imidazoline derivative that...
Clozapine
Clozapine is the prototypical atypical (second-generation) antipsychotic and remains the most effective pharmacological ... MRCPsych exam preparation.
Corticosteroids Pharmacology
Corticosteroids are synthetic analogues of endogenous cortisol with varying ratios of glucocorticoid (anti-inflammatory, metabolic) to mineralocorticoid (sodium retention) activity. In anaesthesia, they are used for...
Desflurane: Pharmacology and Clinical Use
Desflurane is a fluorinated methyl ethyl ether with lowest blood/gas partition coefficient (0.42), providing most rapid emergence of volatile agents. Physical properties : High vapor pressure (669 mmHg at 20°C),...
Dexmedetomidine Pharmacology
Dexmedetomidine is a highly selective alpha-2 adrenoceptor agonist (α2:α1 ratio 1620:1 ) used for sedation in intensive care and procedural settings. It produces "cooperative sedation" via inhibition of noradrenergic...
Dexmedetomidine: Pharmacology and Clinical Use
Dexmedetomidine is a highly selective alpha-2 adrenergic agonist with sedative, anxiolytic, and analgesic properties. Mechanism : Acts on alpha-2A receptors in locus coeruleus (sedation), spinal cord (analgesia), and...
Diazepam: Pharmacology and Clinical Applications in Anaesthesia
Diazepam is a long-acting benzodiazepine that acts as a positive allosteric modulator at the GABA-A receptor, producing anxiolysis, sedation, amnesia, and anticonvulsant effects. Its clinical utility is limited in...
Direct Oral Anticoagulants (DOACs) Pharmacology
Direct Oral Anticoagulants (DOACs), also termed Non-vitamin K Antagonist Oral Anticoagulants (NOACs), represent a pharmacological revolution in anticoagulation therapy, offering predictable pharmacokinetics, fixed...
Drug-Induced Liver Injury
Pattern classification is fundamental: hepatocellular (ALT-predominant), cholestatic (alkaline phosphatase-predominant), or mixed, determined by the R-ratio: (ALT/ULN) ÷ (ALP/ULN). R ≥5 indicates hepatocellular...
Ephedrine Pharmacology
Ephedrine is a non-catecholamine sympathomimetic amine with both direct and indirect actions at alpha and beta adrenergic receptors. It is a naturally occurring alkaloid found in plants of the Ephedra species....
Etomidate Pharmacology
Etomidate is an imidazole-derived intravenous anaesthetic agent distinguished by its remarkable haemodynamic stability, making it the induction agent of choice for patients with cardiovascular compromise or...
Fentanyl
Fentanyl is a synthetic phenylpiperidine opioid agonist with 100× potency of morphine and rapid onset (1-2 minutes IV), making it ideal for intraoperative analgesia and balanced anaesthesia. Mechanism: Selective...
Flumazenil Pharmacology
Flumazenil is a competitive benzodiazepine antagonist at the GABA-A receptor benzodiazepine binding site. Chemically classified as an imidazobenzodiazepine, it reverses the sedative, anxiolytic, and amnestic effects...
Gabapentinoids Pharmacology (Gabapentin and Pregabalin)
Gabapentinoids (gabapentin and pregabalin) are anticonvulsant medications that bind to the α2δ subunit of voltage-gated calcium channels (VGCCs) , reducing presynaptic calcium influx and neurotransmitter release...
Gentamicin Prescribing in Adults
Gentamicin is a bactericidal aminoglycoside antibiotic with potent activity against aerobic Gram-negative bacteria, including Pseudomonas aeruginosa . It is characterized by:
Glyceryl Trinitrate (GTN) Pharmacology
Glyceryl trinitrate (GTN), also known as nitroglycerin, is an organic nitrate vasodilator that has been used clinically for over 150 years for the treatment of angina pectoris and heart failure. It is a triester of...
Glycopyrrolate
Glycopyrrolate is a quaternary ammonium anticholinergic agent with peripheral muscarinic receptor antagonism, used primarily to counteract muscarinic side effects of anticholinesterases during neuromuscular blockade...
Glycopyrrolate Pharmacology
Glycopyrrolate (glycopyrronium bromide) is a synthetic quaternary ammonium anticholinergic agent that acts as a competitive muscarinic receptor antagonist at M1, M2, and M3 receptor subtypes. Its quaternary ammonium...
Hydralazine: Direct Vasodilator Pharmacology and Clinical Use
Hydralazine is a direct-acting arterial vasodilator that relaxes vascular smooth muscle through unclear mechanisms, possibly involving interference with calcium influx and activation of potassium channels. It produces...
Isoflurane Pharmacology
Isoflurane (1-chloro-2,2,2-trifluoroethyl difluoromethyl ether) is a halogenated methyl ethyl ether volatile anaesthetic agent introduced in 1981 that remains widely used globally for maintenance of general...
Ketamine
Ketamine is a phencyclidine (PCP) derivative dissociative anaesthetic producing analgesia, amnesia, and unconsciousness while preserving airway reflexes and cardiovascular stability. Mechanism: Non-competitive...
Ketamine Pharmacology
Ketamine is a phencyclidine derivative dissociative anaesthetic that exists as two stereoisomers: S(+)-ketamine and R(-)-ketamine. The S(+)-enantiomer demonstrates 3-4 times greater analgesic potency and 1.5-2 times...
Lignocaine (Lidocaine)
Lignocaine (lidocaine) is the prototypical amide local anaesthetic, widely used for infiltration, nerve blocks, spinal and epidural anaesthesia, intravenous regional anaesthesia (Bier's block), and as an...
Local Anaesthetics
Local anaesthetics (LAs) block nerve conduction by inhibiting voltage-gated sodium channels (VGSC) in neuronal membranes, preventing action potential generation and propagation. Classification: Esters (procaine,...
Magnesium Pharmacology
Magnesium (Mg²⁺) is the fourth most abundant cation in the body and second most abundant intracellular cation, with critical roles in over 300 enzymatic reactions, neuromuscular transmission, and cardiac...
Malignant Hyperthermia: Recognition and Management
Malignant hyperthermia (MH) is a pharmacogenetic disorder triggered by volatile anaesthetics (sevoflurane, isoflurane, desflurane, halothane) and suxamethonium . Pathophysiology : Ryanodine receptor (RYR1) or DHPR...
Metaraminol Pharmacology
Metaraminol is a synthetic sympathomimetic amine used primarily as a vasopressor for the management of intraoperative hypotension, particularly during spinal anaesthesia for caesarean section. It acts through both...
Midazolam Pharmacology
Midazolam is a water-soluble imidazobenzodiazepine that acts as a positive allosteric modulator of GABA-A receptors at the alpha-gamma subunit interface, enhancing chloride conductance to produce anxiolysis, amnesia,...
Midazolam: Pharmacology and Clinical Use
Midazolam is a short-acting benzodiazepine with anxiolytic, amnestic, sedative-hypnotic, and muscle relaxant properties. Mechanism : Positive allosteric modulation of GABA-A receptors (increases chloride conductance,...
Morphine
Morphine is the prototypical phenanthrene μ-opioid receptor (MOR) agonist, the gold standard against which other opioids are compared. Structure: Phenanthrene backbone (5-ring structure), tertiary amine, two hydroxyl...
Morphine Pharmacology
Morphine is the prototypical natural opioid analgesic derived from the phenanthrene alkaloid class, acting as a full agonist at mu (μ), kappa (κ), and delta (δ) opioid receptors with primary clinical effects mediated...
Neostigmine
Neostigmine is a reversible acetylcholinesterase inhibitor used to reverse non-depolarizing neuromuscular blockade (NMB) by increasing acetylcholine (ACh) concentration at the neuromuscular junction, overcoming...
Neostigmine and Anticholinesterase Pharmacology
Neostigmine is a quaternary ammonium anticholinesterase agent that reversibly inhibits acetylcholinesterase through carbamylation, increasing acetylcholine concentration at the neuromuscular junction to reverse...
Nitrous Oxide Pharmacology
Nitrous oxide (N2O) is a colourless, sweet-smelling inhalational anaesthetic agent with unique physicochemical properties that distinguish it from volatile anaesthetics. Key ANZCA Primary exam points include:...
Nitrous Oxide Pharmacology
Nitrous oxide (N2O) is a colorless, odorless, non-irritating gas and the only inorganic compound used as a general anaesthetic. It is the weakest inhalational anaesthetic with a MAC (minimum alveolar concentration) of...
Noradrenaline (Norepinephrine) Pharmacology
Noradrenaline (norepinephrine) is an endogenous catecholamine and the primary neurotransmitter of the sympathetic nervous system, acting predominantly at alpha-1 adrenoceptors (potent vasoconstriction) with additional...
Ondansetron Pharmacology
Ondansetron is a selective 5-HT₃ (serotonin type 3) receptor antagonist used primarily for the prevention and treatment of postoperative nausea and vomiting (PONV) and chemotherapy-induced nausea and vomiting (CINV)....
Oxycodone and Tramadol Pharmacology
Oxycodone and tramadol represent two distinct approaches to opioid analgesia with fundamentally different pharmacological profiles essential for ANZCA Primary examination. Oxycodone is a semi-synthetic opioid derived...
Phenylephrine Pharmacology
Phenylephrine is a synthetic, non-catecholamine sympathomimetic amine that acts as a selective alpha-1 adrenergic receptor agonist with minimal beta-adrenergic activity. Unlike catecholamines (epinephrine,...
Phenylephrine: Pharmacology and Clinical Use
Phenylephrine is a direct-acting α-1 adrenergic receptor agonist with potent vasoconstrictor effects and no β-activity. Mechanism : Stimulates postsynaptic α-1 receptors on vascular smooth muscle → vasoconstriction →...
Postoperative Nausea and Vomiting Prophylaxis
Postoperative nausea and vomiting (PONV) affects 20-30% of surgical patients and 70-80% of high-risk patients, significantly impacting patient satisfaction, delaying discharge, and increasing costs. Risk...
Propofol
Propofol (2,6-diisopropylphenol) is the most commonly used intravenous anaesthetic agent for induction and maintenance of general anaesthesia and sedation in ICU. Structure: Simple phenol derivative with two isopropyl...
Propofol Pharmacology
Propofol (2,6-diisopropylphenol) is a phenol derivative intravenous anaesthetic that acts primarily as a positive allosteric modulator of GABA A receptors, particularly at the beta-subunit, increasing chloride...
Remifentanil Pharmacology
Remifentanil is a synthetic ultra-short-acting mu-opioid agonist distinguished by its unique ester linkage that allows rapid hydrolysis by non-specific tissue and plasma esterases, resulting in organ-independent...
Rocuronium
Rocuronium is an aminosteroid non-depolarizing neuromuscular blocking agent (NMBA) with rapid onset (60-90 seconds) making it suitable for rapid sequence intubation (RSI) when succinylcholine contraindicated....
Sevoflurane
Sevoflurane is a fluorinated ether inhalational anaesthetic with blood:gas partition coefficient 0.65 (low solubility), enabling rapid induction and emergence compared to isoflurane (1.4) and halothane (2.4). MAC...
Sodium Nitroprusside Pharmacology
Sodium nitroprusside (SNP) is a potent, rapid-acting, direct-acting vasodilator that produces arteriolar and venous dilation through non-specific release of nitric oxide (NO). It is a complex inorganic compound...
Sugammadex Pharmacology
Sugammadex is a modified gamma-cyclodextrin designed specifically to encapsulate and inactivate steroidal neuromuscular blocking agents (rocuronium vecuronium pancuronium), providing rapid and complete reversal of...
Suxamethonium (Succinylcholine)
Suxamethonium (succinylcholine) is the only depolarizing neuromuscular blocker in clinical use, providing rapid onset (30-60 seconds) and ultra-short duration (5-10 minutes) ideal for rapid sequence intubation....
Thiopentone (Thiopental) Pharmacology
Thiopentone (thiopental sodium) is a thiobarbiturate intravenous anaesthetic agent that was the original gold standard for anaesthetic induction for over 50 years before propofol's dominance. Its structure features a...
Total Intravenous Anaesthesia (TIVA) and Target Controlled Infusion (TCI)
Total intravenous anaesthesia (TIVA) provides complete anaesthesia without volatile agents using continuous IV drug infusions, offering advantages in PONV reduction (50% lower than volatiles), neurosurgery (reduced...
Tranexamic Acid Pharmacology
Tranexamic acid (TXA) is a synthetic lysine analogue antifibrinolytic agent that competitively inhibits plasminogen activation by blocking lysine-binding sites, thereby preventing fibrin clot degradation. TXA is...
Vasopressin and Analogues Pharmacology
Vasopressin (arginine vasopressin, AVP), also known as antidiuretic hormone (ADH), is an endogenous nonapeptide synthesised in the hypothalamic supraoptic and paraventricular nuclei and released from the posterior...
Vecuronium: Pharmacology and Clinical Use
Vecuronium is an intermediate-acting aminosteroid non-depolarizing neuromuscular blocker . Structure : Steroid nucleus with quaternary ammonium groups (bisquaternary). Mechanism : Competitive antagonist at nicotinic...