Drug Types, MoA and Interactions Flashcards
What is the mechanism of action of olanzapine?
antagonises serotonin (5HT2A/2C, 5HT3, 5HT6), dopamine (D1, D2, D3, D4, D5) and cholinergic muscarinic receptors
What type of drug is olanzapine?
atypical antipsychotic, anti-manic and mood stabilising agent
What type of drug is droperidol?
Antipsychotic
What is the mechanism of action of droperidol?
Competitively blocks D2 receptors in the mesolimbic system causing an increased turnover of brain dopamine to produce antipsychotic effect
- Potent D2 (dopamine receptor) antagonist with some histamine and serotonin antagonist activity.
- Competitively blocks D2 receptors in the mesolimbic system causing an increased turnover of brain dopamine to produce an antipsychotic effect.
- Causes Central Nervous System (CNS) depression at subcortical levels of the brain, midbrain, and brainstem reticular formation.
- Antiemetic effect occurs by acting via D2 receptors in the stomach and Chemoreceptor Trigger Zones (CTZ).
- The blood pressure is lowered, in part as a direct vasodilator effect and in part because of adrenergic blockade.
Mesolimbic system is a CNS circuit
What drugs does droperidol interact with?
- May increase the action of sedatives and opiates
- May increase the action of anti-hypertensive agents and orthostatic hypotension may occur.
What drugs does olanzapine interact with?
Sedatives/alcohol: Over sedation due to synergistic effects. Avoid combination where possible.
What type of drug is ketamine?
anaesthetic agent
What is the mechanism of action of ketamine?
- Antagonises N-methyl-D-aspartate (NMDA) receptors
- interacts with muscarinic receptors, descending monoaminergic pain pathways, voltage-sensitive calcium channels and opioid receptors in brain and spinal cord
What are the interactions of ketamine?
- Other central nervous system (CNS) depressants (e.g. ethanol) can potentiate CNS depression and/or increased risk of developing respiratory depression.
- Benzodiazepines may prolong the half-life of ketamine.
What type of drug is midazolam?
benzodiazepine
What are the interactions of midazolam?
Concomitant use of barbiturates, alcohol or other central nervous system depressants
These increase the risk of underventilation or apnoea and/or cardio-ventricular depression and may contribute to a profound and/or prolonged drug effect, that could result in coma or death.
What is the mechanism of action of midazolam?
Enhanbces the action of the inhibitory neurotransmitter GABA across all levels of the CNS
What type of drug is fentanyl?
a pure opioid agonist
What is the mechanism of action of fentanyl?
Acts primarily on mu-opioid receptors in the brain, spinal cord and smooth muscle.
- Produces analgesia, anxiolysis, respiratory depression, sedation and constipation.
- Secondary actions include increase in the tone and decrease in the contractions of the gastrointestinal smooth muscle, which results in prolongation of gastrointestinal transit time and may be responsible for the constipatory effect of opioids.
- All opioid mu-receptor agonists, including fentanyl, produce dose dependent respiratory depression. The risk of respiratory depression is less in patients with pain and those receiving chronic opioid therapy who develop tolerance to respiratory depression and other opioid effects.
What are the interactions with fentanyl?
Use with caution and consider reduced dosages when using concurrently with patients receiving other central nervous system depressants (including alcohol), due to the risk of profound sedation, respiratory depression and hypotension.
What type of drug is hydrocortisone?
anti-inflammatory adrenocortical steroid
What is the mechanism of action of hydrocortisone?
anti-inflammatory and immunosuppressive actions due to its ability to suppress certain leukocytes and reverse the increased capillary permeability associated with immune responses
What drugs does hydrocortisone interact with?
aspirin
hepatic enzyme inducers (phenobarbitone)
oral contraceptives
antifungals
What type of drug is fentanyl?
Synthetic narcotic analgesic (opioid)
What is the mechanism of action of fentanyl?
Binds to opioid receptors (mainly mu-opioid) in the CNS and GIT reducing the transmission of pain impulses and modulates the descending inhibitory pathways from the brain.
What type of drug is morphine?
narcotic analgesic
What is the mechanism of action of morphine?
Binds to opioid receptors (mainly mu-opioid) in the CNS and GIT reducing the transmission of pain impulses and modulates the descending inhibitory pathways from the brain.
What type of drug is naloxone?
opioid antagonist
What is the mechanism of action of naloxone?
antagonises the opioid effects by competing for the same receptor sites
What type of drug is adrenaline?
sympathomimetic
What is the mechanism of action of adrenaline?
- Stimulates the ALPHA and BETA receptors of the sympathetic nervous system causing “Fight or Flight” reaction
- α1 stimulation causes peripheral vasoconstriction, raising the perfusion pressure of vital organs during cardiac arrest and decreases capillary permeability and increases blood pressure in anaphylaxis
- β1 stimulation increases myocardial excitability, tachycardia and myocardial contractility
- β2 stimulation causes bronchodilation
What type of drug is salbutamol?
sympathomimetic
What is the mechanism of action of salbutamol?
stimulates B2 receptors in bronchial smooth muscle resulting in bronchodilation
What type of drug is glucagon?
pancreatic hormone
What is the mechanism of action of glucagon?
converts liver glycogen to glucose
What type of drug is compound sodium lactate?
Crystalloid solution containing sodium chloride, calcium, potassium and lactate
What is the mechanism of action of compound sodium lactate?
distributed throughout extracellular fluid space, approximately 25% stays in the intravascular space for a variable period of time
