Common Drugs to Know for Anaesthetic

Brief Notes on Drugs used in Anaesthetics Midazolam • • • • Class: Benzothiazine (general anaesthetics). Indications: preoperative sedation or induction of general anaesthesia. Route of administration: IV injections. Dosage: - Children: IV injection should be given over 2-3 minutes, and then wait an additional 2-3 minutes to fully evaluate sedative effect before initiating a procedure or repeating a dose. Do not give to neonates. - Adults: administer 1 mg/mL solution over more than 2 minutes; allow more than 2 minutes to evaluate sedative effect. Initial dose should not exceed 2.5mg (or 1.5 mg in patient that are over 60 or are chronically ill or debilitated patients. • Mechanism of action: enhances opening of GABA receptors. Fentanyl • • • Class: opiate agonist Administration: IM or IV injection or IV infusion. Dosage: use the lowest dosage and shortest duration of therapy consistent with treatment goals for the patient. ANAESTHESIA • • IV or IM - Low dose: 2 mcg/kg. - Moderate dose: 2-20 mcg/kg - High: 20-50 mcg/kg IV infusion - Initial loading dose: 4-20mcg/kg. - Maintenance 2-20mcg/kg. ANALGESIA • • Preoperatively: 50-100 mcg IM 30-60 minutes prior to surgery. Postoperatively: 50 – 100 mcg IM every 1-2 hours in the recovery room as needed. Remifentanil • • Classification: opiate antagonist. Dosage: - Use controlled injection device to ensure precise control of flow rate during continuous IV infusions of the drug. - IV infusions for induction in general anaesthesia: 0.5-1 mcg/kg per minute given in conjunction with a volatile anaesthetic or hypnotic agent in patients with ASA physical status; I, II and III. - IV infusions for maintenance in general anaesthesia: use in conjunction with 66% N2O, use at a dose of 0.4 mcg/kg per minute in patients with an ASA of I, II and III. Recommended infusion at a rate of 0.05-2 mcg/kg per minute is recommended. Oxycodone • • • Classification: opiate agonist. Dosage: 5-15 mcg every 4 to 6 hours as needed for opiate native patients. - When discontinuing following long-term therapies -> general you should reduce the dosage by 25-50% per day. Mechanism of action: mainly on the CNS and intestines. - Acts at several sites in the CNS involving the neurotransmitters that produce neurotransmitters. Tramadol • • • Classification: opiate agonist. Administration: orally alone or in fixed combination with acetaminophen. Dosage: use lowest effective dose and shortest duration of therapy consistent with treatment goals of the patient. Propofol • • • Administration: IV infusion or IV injection. - Administer slowly to minimise adverse effects. - For iv injection: administer in incremental doses. - When administered as an IV infusion, adjust the rate of infusion according to individual requirements. Uses: associated with anticonvulsant effects, hypnotic doses many be associated with analgesic effects, IV induction and maintenance of general anaesthesia. - Can be use for procedural sedation. General associated with similar of faster time to recovery from anaesthesia, more rapid recovery of psychomotor performance and time to discharge as well as lower incidence of adverse effects such as nausea and vomit, compared to other IV anaesthetic agents. Suxamethonium • • • Classification: muscle relaxant. Uses: during induction. Mechanism of action: depolarising muscle relaxant • Dosage: ideal dose for intubation is 1.0-1.5 mg/kg. - For short procedure: 0.3-1.1mg/kg. Cisatracurium • • • • • Classification: skeletal muscle relaxation. Administration: IV only. Dosage: - Initial (intubation): 0.15 or 0.2 mg/kg. - Maintenance:3mcg/kg per minute. Uses: for muscle relaxation after general anaesthesia has bene induced. Mechanism of action: Rocuronium • • • • • Classification: intermediate acting non-depolarising skeletal muscle relaxant. Uses: for rapid sequence intubation when the use of succinylcholine is contraindicated. - It is used for skeletal muscle relaxation during surgery after general anaesthesia has been induced. Administration: IV. Dosage: - 0.6 mg/kg. - May use a lower initial dose of 0.45 mg/kg. - If a larger initial dose is needed 0.9 or 1.2mg/kg. Mechanism of action: Neostigmine • • • • • Classification: PSNS cholinergic agents. Uses: reversal of effects of nondepolarizing neuromuscular blocking agents. Administration: administer by slow IV for a period of at least 1 minute. - Also has been administered by IM or sub-Q injection. Dosage: - IV: 0.03 – 0.07mg/kg is usually enough to achieve adequate recovery of neuromuscular function within 10 to 20 minutes. - To reverse longer acting agents such as pancuronium and vecuronium or deeper blocks then 0.07 mg/kg recommended. Mechanism of action: Metaraminol • • Classification: vasopressor. Stimulate NA receptors or NA release. Clonidine • Alpha-2-adrenegeric agonist in the NTS used to treat hypertension, ADHD and neuropathic pain -> stops binding of NA and A -> treats hypertension by lowering the blood pressure. - Stimulation of these receptors in the dorsal horn reduces pain transmission. Atropine • • • • Administration: sub-Q, IM or IV. - It is better to give it quickly, because slow administration may cause a paradoxical slowing of the heart. Dosage: 0.5-1 mg administered for 30-60 minutes prior to surgery. - May repeat in 1-2 hours. Uses: inhibits salivation and excessive secretions of the respiratory tract. Mechanism of action: Dexamethasone • • • Classification: glucocorticoid Mechanism of action has anti-inflammatory and immunosuppressant properties. Used to reduce nausea and vomiting after surgery and to relieve pain. - Acts as an anti-emetic as it reduces the expression of serotonin receptors. Ondansetron • 5-HT3 antagonist