Pharma control 1 Opiods

Codeine

Source Group: Opioid analgesics. Classification: Weak opioid analgesic; prodrug and predominantly μ-opioid receptor agonist through conversion to morphine. Mechanism of Action: Metabolized partly by CYP2D6 to morphine, which activates μ-opioid receptors and decreases neurotransmitter release in pain pathways. Therapeutic Use: Mild-to-moderate pain and, in selected formulations, cough suppression. Adverse Effects: Sedation, nausea, vomiting, constipation, miosis, respiratory depression, dependence. Contraindications: Significant respiratory depression, acute severe asthma without monitoring, paralytic ileus, children under 12 years, and use after tonsillectomy/adenoidectomy in children.

Buprenorphine

Source Group: Opioid analgesics. Classification: Partial μ-opioid receptor agonist and κ-opioid receptor antagonist. Mechanism of Action: Binds μ receptors with very high affinity but produces only partial receptor activation; reduces opioid craving and withdrawal while showing a ceiling effect on respiratory depression. Therapeutic Use: Opioid-use disorder and moderate-to-severe chronic pain. Adverse Effects: Sedation, nausea, constipation, dizziness, respiratory depression, precipitated opioid withdrawal. Contraindications: Severe respiratory depression, acute severe asthma without monitoring, significant hepatic impairment; may precipitate withdrawal if given too soon after a full opioid agonist.

Fentanyl

Source Group: Opioid analgesics; General anaesthetics. Classification: Potent synthetic full μ-opioid receptor agonist. Mechanism of Action: Strongly activates μ-opioid receptors, decreasing presynaptic Ca2+ entry and increasing postsynaptic K+ efflux, thereby suppressing pain transmission. Therapeutic Use: Severe pain, perioperative analgesia, anaesthetic adjunct, procedural sedation. Adverse Effects: Profound respiratory depression, sedation, nausea, constipation, bradycardia, chest-wall rigidity at high rapid IV doses. Contraindications: Significant respiratory depression, acute severe asthma without respiratory support, paralytic ileus.

Loperamide

Source Group: Opioid analgesics. Classification: Peripherally acting μ-opioid receptor agonist; antidiarrhoeal opioid. Mechanism of Action: Activates μ receptors in the intestinal wall, reducing propulsive peristalsis and increasing intestinal transit time; normally has minimal CNS penetration. Therapeutic Use: Acute and chronic diarrhoea. Adverse Effects: Constipation, abdominal cramps, nausea, ileus; serious cardiac arrhythmias with very high doses or abuse. Contraindications: Bloody diarrhoea, acute ulcerative colitis, invasive bacterial enterocolitis, C. difficile-associated diarrhoea, intestinal obstruction, children under 2 years.

Methadone

Source Group: Opioid analgesics. Classification: Long-acting synthetic full μ-opioid receptor agonist; also NMDA receptor antagonist. Mechanism of Action: Activates μ-opioid receptors and also antagonizes NMDA receptors and inhibits monoamine reuptake. Therapeutic Use: Opioid-use disorder maintenance/detoxification and severe chronic pain. Adverse Effects: Respiratory depression, sedation, constipation, nausea, dependence, QT prolongation and torsades de pointes. Contraindications: Significant respiratory depression, acute severe asthma without monitoring, paralytic ileus; major caution with prolonged QT interval or interacting QT-prolonging drugs.

Morphine

Source Group: Opioid analgesics; General anaesthetics. Classification: Strong full μ-opioid receptor agonist. Mechanism of Action: Activates μ-opioid receptors, inhibiting neurotransmitter release and neuronal firing in ascending pain pathways. Therapeutic Use: Severe acute and chronic pain, perioperative analgesia, palliative care; adjunct during anaesthesia. Adverse Effects: Respiratory depression, sedation, nausea, vomiting, constipation, miosis, hypotension, pruritus, urinary retention, dependence. Contraindications: Significant respiratory depression, acute severe asthma without monitoring, paralytic ileus; caution with raised intracranial pressure and severe hypotension.

Naloxone

Source Group: Opioid analgesics. Classification: Competitive opioid receptor antagonist; strongest functional importance at μ receptors. Mechanism of Action: Competitively displaces opioid agonists from opioid receptors and rapidly reverses their CNS and respiratory effects. Therapeutic Use: Emergency reversal of opioid overdose and opioid-induced respiratory depression. Adverse Effects: Acute opioid withdrawal, agitation, nausea, vomiting, tachycardia, hypertension; rarely pulmonary oedema or arrhythmias. Contraindications: Essentially no absolute contraindication in life-threatening opioid overdose apart from hypersensitivity; use cautiously in opioid-dependent patients because abrupt withdrawal may occur.

Pentazocine

Source Group: Opioid analgesics. Classification: Mixed opioid agonist-antagonist; mainly κ-opioid receptor agonist with weak μ antagonist/partial agonist activity. Mechanism of Action: Activates κ receptors to produce analgesia while producing limited or antagonistic activity at μ receptors. Therapeutic Use: Moderate-to-severe pain. Adverse Effects: Sedation, nausea, dizziness, respiratory depression, dysphoria, hallucinations, increased heart rate and blood pressure. Contraindications: Significant respiratory depression, acute severe asthma, paralytic ileus; may precipitate withdrawal in patients dependent on full μ agonists.

Benzocaine

Source Group: Local anaesthetics. Classification: Ester-type local anaesthetic. Mechanism of Action: Reversibly blocks voltage-gated Na+ channels in sensory nerves, preventing action-potential initiation and propagation. Therapeutic Use: Topical anaesthesia of skin and mucous membranes. Adverse Effects: Methemoglobinaemia, local irritation, allergic reactions, contact dermatitis. Contraindications: Hypersensitivity to ester local anaesthetics or PABA-related compounds, known methemoglobinaemia; avoid routine use in children under 2 years.

Bupivacaine

Source Group: Local anaesthetics. Classification: Long-acting amide-type local anaesthetic. Mechanism of Action: Blocks voltage-gated Na+ channels and prevents nerve depolarization and conduction. Therapeutic Use: Epidural, spinal, peripheral nerve block and local infiltration anaesthesia. Adverse Effects: CNS toxicity, seizures, hypotension, bradycardia, severe ventricular arrhythmias and cardiotoxicity. Contraindications: Hypersensitivity to amide local anaesthetics; avoid intravenous regional anaesthesia because of severe cardiotoxicity; contraindicated for obstetric paracervical block.

Cocaine

Source Group: Local anaesthetics. Classification: Ester-type local anaesthetic and sympathomimetic monoamine reuptake inhibitor. Mechanism of Action: Blocks voltage-gated Na+ channels while also inhibiting norepinephrine, dopamine and serotonin reuptake; unlike most local anaesthetics, causes vasoconstriction. Therapeutic Use: Topical local anaesthesia and vasoconstriction during selected ENT procedures. Adverse Effects: Hypertension, tachycardia, arrhythmias, myocardial ischaemia, seizures, agitation, dependence. Contraindications: Severe hypertension, significant coronary artery disease or arrhythmias; avoid dangerous sympathomimetic drug combinations.

Lidocaine

Source Group: Local anaesthetics. Classification: Amide-type local anaesthetic; also Class Ib antiarrhythmic. Mechanism of Action: Blocks voltage-gated Na+ channels, preventing neuronal action-potential propagation; in cardiac tissue preferentially suppresses depolarized ventricular tissue. Therapeutic Use: Local infiltration, regional nerve blocks, topical anaesthesia; ventricular arrhythmias when given systemically. Adverse Effects: Circumoral numbness, tinnitus, metallic taste, confusion, seizures, hypotension, bradycardia and arrhythmias at toxic doses. Contraindications: Hypersensitivity to amide local anaesthetics; systemic use is contraindicated in certain severe conduction blocks without a pacemaker.

Mepivacaine

Source Group: Local anaesthetics. Classification: Intermediate-acting amide-type local anaesthetic. Mechanism of Action: Reversibly blocks voltage-gated Na+ channels, inhibiting nerve impulse conduction. Therapeutic Use: Local infiltration, dental anaesthesia and peripheral nerve blocks. Adverse Effects: CNS excitation followed by depression, seizures, dizziness, hypotension, bradycardia, arrhythmias. Contraindications: Hypersensitivity to amide local anaesthetics; caution with severe cardiac conduction abnormalities and severe hepatic impairment.

Procaine

Source Group: Local anaesthetics. Classification: Short-acting ester-type local anaesthetic. Mechanism of Action: Blocks voltage-gated Na+ channels and prevents nerve depolarization; rapidly hydrolysed by plasma pseudocholinesterase. Therapeutic Use: Local infiltration and regional anaesthesia; now used less commonly than amide agents. Adverse Effects: Allergic reactions, hypotension, CNS toxicity, seizures; PABA metabolite may produce hypersensitivity. Contraindications: Hypersensitivity to ester local anaesthetics or PABA-related compounds; caution with pseudocholinesterase deficiency.

Diazepam

Source Group: General anaesthetics; Anxiolytics, hypnotics. Classification: Long-acting benzodiazepine. Mechanism of Action: Positive allosteric modulator of GABA-A receptors; increases the frequency of GABA-mediated Cl− channel opening. Therapeutic Use: Anxiety, acute seizures/status epilepticus, alcohol withdrawal, muscle spasm, preoperative sedation and anaesthetic adjunct. Adverse Effects: Sedation, impaired coordination, anterograde amnesia, respiratory depression especially with opioids, dependence and withdrawal. Contraindications: Severe respiratory insufficiency, sleep apnoea, myasthenia gravis, severe hepatic insufficiency; avoid combining with other major CNS depressants when possible.

Halothane

Source Group: General anaesthetics. Classification: Volatile halogenated inhalational general anaesthetic. Mechanism of Action: Enhances inhibitory CNS signalling and suppresses excitatory neuronal activity through multiple ion-channel targets. Therapeutic Use: Induction and maintenance of general anaesthesia; now largely replaced by safer volatile anaesthetics. Adverse Effects: Hypotension, myocardial depression, arrhythmias, respiratory depression, malignant hyperthermia, severe halothane hepatitis. Contraindications: Previous halothane-associated hepatitis or unexplained jaundice after exposure, susceptibility to malignant hyperthermia.

Ketamine

Source Group: General anaesthetics. Classification: Dissociative intravenous general anaesthetic; noncompetitive NMDA receptor antagonist. Mechanism of Action: Blocks NMDA glutamate receptors, producing dissociative anaesthesia, profound analgesia and amnesia while generally preserving airway reflexes and sympathetic tone. Therapeutic Use: Anaesthetic induction, procedural sedation, trauma/emergency anaesthesia, analgesia. Adverse Effects: Hypertension, tachycardia, hypersalivation, nausea, emergence reactions, hallucinations, increased muscle tone. Contraindications: Situations in which a substantial increase in blood pressure would create serious risk; caution with severe cardiovascular disease or psychosis.

Midazolam

Source Group: General anaesthetics; Anxiolytics, hypnotics. Classification: Short-acting benzodiazepine. Mechanism of Action: Positive allosteric modulator of GABA-A receptors that increases the frequency of Cl− channel opening. Therapeutic Use: Procedural sedation, preoperative anxiolysis, anaesthetic induction/adjunct, acute seizure treatment. Adverse Effects: Respiratory depression, hypotension, sedation, anterograde amnesia, paradoxical agitation. Contraindications: Severe respiratory depression without airway support, significant hypersensitivity; caution with severe hepatic impairment and other CNS depressants.

Nitrous oxide

Source Group: General anaesthetics. Classification: Inhalational gaseous general anaesthetic and analgesic. Mechanism of Action: Produces analgesia and sedation largely through NMDA receptor antagonism and modulation of other CNS pathways; has weak anaesthetic potency. Therapeutic Use: Analgesia and sedation in dentistry, obstetrics and minor procedures; adjunct to other general anaesthetics. Adverse Effects: Nausea, vomiting, dizziness, diffusion hypoxia, expansion of trapped gas spaces; chronic exposure can cause functional vitamin B12 deficiency and neurological toxicity. Contraindications: Pneumothorax, bowel obstruction, middle-ear surgery or other closed gas-containing spaces, severe vitamin B12 deficiency.

Propofol

Source Group: General anaesthetics. Classification: Rapid-acting intravenous general anaesthetic and sedative-hypnotic. Mechanism of Action: Potentiates GABA-A receptor activity, increasing inhibitory neurotransmission in the CNS. Therapeutic Use: Induction and maintenance of general anaesthesia, procedural sedation, ICU sedation. Adverse Effects: Hypotension, respiratory depression/apnoea, bradycardia, pain on injection, hypertriglyceridaemia; prolonged high-dose infusion may cause propofol infusion syndrome. Contraindications: Hypersensitivity to propofol or formulation components; major caution in profound haemodynamic instability.

Thiopental

Source Group: General anaesthetics; Anxiolytics, hypnotics. Classification: Ultra-short-acting barbiturate; intravenous general anaesthetic. Mechanism of Action: Positive allosteric modulator of GABA-A receptors; prolongs the duration of Cl− channel opening and causes rapid CNS depression. Therapeutic Use: Rapid induction of general anaesthesia and selected situations requiring reduction of intracranial pressure; historically used for severe seizures. Adverse Effects: Respiratory depression, apnoea, hypotension, myocardial depression, prolonged sedation, tissue injury after extravasation. Contraindications: Acute porphyrias, severe cardiovascular collapse, severe respiratory depression, barbiturate hypersensitivity.

Alprazolam

Source Group: Anxiolytics, hypnotics. Classification: Intermediate-acting benzodiazepine. Mechanism of Action: Positive allosteric modulator of GABA-A receptors, increasing frequency of GABA-mediated Cl− channel opening. Therapeutic Use: Anxiety disorders and panic disorder. Adverse Effects: Sedation, dizziness, impaired coordination, memory impairment, dependence, withdrawal seizures, respiratory depression with other CNS depressants. Contraindications: Severe respiratory insufficiency; major caution with opioids and other sedatives; contraindicated with certain strong CYP3A inhibitors.

Buspirone

Source Group: Anxiolytics, hypnotics. Classification: Non-benzodiazepine anxiolytic; partial 5-HT1A receptor agonist. Mechanism of Action: Partially activates presynaptic and postsynaptic 5-HT1A receptors, gradually modifying serotonergic signalling without significant GABA-mediated sedation. Therapeutic Use: Generalized anxiety disorder and chronic anxiety. Adverse Effects: Dizziness, headache, nausea, nervousness, light-headedness; minimal sedation and dependence compared with benzodiazepines. Contraindications: MAO inhibitor use within 14 days; caution or avoidance in severe hepatic or renal impairment.

Flumazenil

Source Group: Anxiolytics, hypnotics. Classification: Competitive benzodiazepine-site antagonist at the GABA-A receptor. Mechanism of Action: Competitively blocks the benzodiazepine binding site and reverses benzodiazepine-induced CNS depression. Therapeutic Use: Reversal of benzodiazepine sedation and selected benzodiazepine overdoses. Adverse Effects: Seizures, agitation, anxiety, nausea, dizziness, acute benzodiazepine withdrawal. Contraindications: Benzodiazepine-dependent patients at high seizure risk, mixed overdose with proconvulsant drugs such as tricyclic antidepressants, or when benzodiazepines are being used to control a life-threatening condition.

Lorazepam

Source Group: Anxiolytics, hypnotics. Classification: Intermediate-acting benzodiazepine. Mechanism of Action: Potentiates GABA-A receptor activity and increases the frequency of Cl− channel opening. Therapeutic Use: Anxiety, status epilepticus, acute agitation, alcohol withdrawal, preoperative sedation. Adverse Effects: Sedation, dizziness, anterograde amnesia, impaired coordination, respiratory depression, dependence. Contraindications: Severe respiratory insufficiency, sleep apnoea, myasthenia gravis; caution with opioids and other CNS depressants.

Phenobarbital

Source Group: Anxiolytics, hypnotics. Classification: Long-acting barbiturate; sedative-hypnotic and antiepileptic. Mechanism of Action: Positive allosteric modulator of GABA-A receptors that prolongs Cl− channel opening; at high concentrations can directly activate GABA-A receptors. Therapeutic Use: Epilepsy/seizure control, including selected neonatal seizures; historically used as a sedative-hypnotic. Adverse Effects: Sedation, cognitive impairment, respiratory depression, hypotension, tolerance, dependence, hepatic enzyme induction. Contraindications: Acute porphyrias, severe respiratory depression, severe hepatic impairment, barbiturate hypersensitivity.

Triazolam

Source Group: Anxiolytics, hypnotics. Classification: Short-acting benzodiazepine hypnotic. Mechanism of Action: Potentiates GABA-A receptor activity and increases frequency of GABA-mediated Cl− channel opening. Therapeutic Use: Short-term treatment of insomnia. Adverse Effects: Sedation, anterograde amnesia, rebound insomnia, confusion, impaired coordination, dependence. Contraindications: Use with potent CYP3A inhibitors, severe respiratory insufficiency; major caution with opioids and other CNS depressants.

Zolpidem

Source Group: Anxiolytics, hypnotics. Classification: Non-benzodiazepine hypnotic; Z-drug; preferential GABA-A α1-subunit positive allosteric modulator. Mechanism of Action: Binds the benzodiazepine site on GABA-A receptors with relative preference for α1-containing receptors, enhancing inhibitory Cl− currents and promoting sleep. Therapeutic Use: Short-term treatment of insomnia. Adverse Effects: Drowsiness, dizziness, anterograde amnesia, next-day impairment, hallucinations, complex sleep behaviours, dependence. Contraindications: Previous complex sleep behaviour caused by zolpidem, hypersensitivity; avoid or use extreme caution with severe respiratory depression and other potent CNS depressan