GIT and neuro drugs Flashcards
List the 3 neurological disorders?
- Focal seizures
- General seizures
- Status epilepticus
What are the 5 neurological drug types?
- Phenobarbital
- Levetiracetam
- Potassium bromide
- Benzodiazepines
- Imepitoin
What are the 2 gastrointestinal drug types?
- Emetics/antiemetics/prokinetic drugs
- Antacids/antiulcer
What are phenobarbitals?
- First choice of antiepileptic drug
- Decreases likelihood of spontaneous depolarization of brain cells
- POM-V Schedule 3
Give 2 examples of a phenobabital?
- Epiphen solution
- Phenoleptil
What are the pharmacodynamics of phenobarbitals?
- Mediates its use through GABA receptors
- Inhibits the release of excitatory neurotransmitter glutamate
- Effects reduce neuronal excitability
What are the pharmacokinetics of phenobarbitals?
- Rapidly absorbed orally
- Metabolised by the liver
- Excreted by kidneys
What are the adverse reactions of phenobarbitals?
- Ataxia
- Polyphagia
- PUPD
- Hepatic toxicity
- Anaemia/neutropenia/thrombocytopenia
What are the contraindications of phenobarbitals?
- Pregnant or nursing animals
- Hepatic disease
What are imepitoins?
- Also first choice to manage idiopathic epilepsy
- POM-V
Give an example of an imepitoin?
- Pexion tablets
What are the pharmacodynamics of imepitons?
- Inhibit GABA receptors to stop seizures
What are the pharmacokinetics of imepitoins?
- Metabolised by the liver
- Eliminated through faeces more than urine
What are the adverse reactions of imepitoins?
- Ataxia
- Skin reactions
- Polyphagia
- Hyperactivity
- PUPD
- Hypersalivation
- D+/V+
- Decreased sight
What are levetiracetams?
- Used as adjunctive maintenance therapy alongside other drugs
- POM, as not licensed as Keppra
Give an example of an levetiracetam
- Keppra
What are the pharmacodynamics of levetiracetams?
- Unknown mechanism
- Possible binding to presynaptic vesicle proteins in the brain
What are the pharmacokinetics of levetiracetams?
- Rapidly absorbed through GIT
- Can be administered rectally for same effects
What are the adverse reactions of levetiracetams?
- Ataxia
- Reduced appetite
- Hypersalivation
- Lethargy
What is the contraindication of levetiracetams?
- Do not use in severe renal disease
What are benzodiazepines (diazepam)?
- Anticonvulsant for short-term emergency control of severe epilepsy or status epilepticus
- Anxiolytic
- POM-V
What are the pharmacodynamics of benzodiazepines (diazepam)?
- Inhibition of centrally acting neurotransmitters through GABA receptors
What are the pharmacokientics of benzodiazepines (diazepam)?
- Metabolised by the liver into active metabolites, which are likely to accumulate
- Eliminated in the urine
What are the adverse reactions of benzodiazepines (diazepam)?
- Ataxia
- Excitation
What is the contraindication of benzodiazpines (diazepam0?
- Severe hepatic disease
What are benzodiazepines (midazolam)?
- Provides sedation with amnesia
- Emergency control of seizures
- POM, as not licensed
What are the pharmacodynamics of benzodiazepines (midazolam)?
- Neural inhibition by increasing the effects of GABA
What are the pharmacokinetics of benzodiazepines (midazolam)?
- Metabolised by the liver in to inactive metabolites, so less likely to accumulate
- Eliminated in the urine
What are the adverse reactions of benzodiazepines (midazolam)?
- Hypotension
- Respiratory depression
What is the contraindication of benzodiazepines (midazolam)?
- Neonates
What are emetics?
- Self-limiting emesis
- POM-V
Give examples of emetics
- Apomorphine as apometic
- Emedog
What are the pharmacodynamics of emetics?
- Stimulates emesis through D2 dopamine receptors in the chemoreceptor trigger zone
What are the pharmacokinetics of emetics?
- Metabolised by the liver
- Excreted in urine and breast milk
What are the adverse reactions of emetics?
- V++++
- Respiratory depression
- Sedation
- Hypotension
What are the contraindications of emetics?
- If caustic products have been ingested
- FB blockage
- Unconscious
- Seizures or poison
- Collies due to MDR1 gene, which causes sensitivity to ivermectin
What are antiemetics?
- Prevents vomiting
- POM-V
Give examples of antiemetics
- Cerenia
- Prevomax
- Vetemax
What are the pharmacodynamics of antiemetics?
- Inhibits vomiting reflex by blocking NK-1 receptors in medullary vomiting centre
What are the pharmacokinetics of antiemetics?
- Metabolised by the liver
- Eliminated through kidneys and faeces
What are the adverse reactions of antiemetics?
- Pain in injection
- Haemolysis if high doses
What are contraindications of antiemetics?
- GIT obstruction or perforation
What are prokinetics?
- Treatment of vomiting
- POM-V
What are examples of prokinetics?
- Metoclopramide as emeprid, metomotyl and vomend
What are the pharmacodynamics of prokinetics?
- Affects gastric tissues through acetylcholine, which increases peristaltic activity
What are the pharmacokinetics of prokinetics?
- Metabolised by the liver
- Eliminated through urine
What are the adverse reactions of prokinetics?
- Agitation
- Ataxia
- Tremors
- Aggression
- Vocalisation
- Disorientation
What are the contraindications of prokinetics?
- Avoid in GIT obstruction and haemorrhage
- Epilepsy
- Renal or hepatic disease
- Pseudopregnancy
What are H2 blockers?
- Management of gastritis, gastric or duodenal ulcers, oesophagitis and mast cell neoplasia
- POM-V
Give an example of an H2 blocker?
- Cimetidine as Zitac
What are the pharmacodynamics of H2 blcokers?
- Histamine receptor antagonist reduces histamine-induced gastric acid secretion
What are the pharmacokinetics of H2 blockers?
- Metabolised by the liver
- Excreted by urine
What are the adverse reactions of H2 blockers?
- Thromobocytopenia
- Hepatotoxicity
- Nephrotoxicity
What are proton-pump inhibitors?
- Management of gastric or duodenal ulcers, oesophagitis, mast cell neoplasia
- POM-V
Give an example of a proton-pump inhibitor
- Omeprazole as Gastrogard
- Can use Omeprazole off license
What are the pharmacodynamics of proton-pump inhibitors?
- Reduction of gastric acid thtough the inhibition of proton pumps producing hydrogen ions
What are the pharmacokinetics of proton-pump inhibitors?
- Metabolised by the liver
- Eliminated through urine and bile to faeces
What are anti-ulcers?
- Treatment of oesophageal, gastric and duodenal ulceration
- POM, as not licensed as Antepsin
Give an example of an anti-ulcer
- Sucralfate
What are the pharmacodynamics of anti-ulcers?
- Aluminium ion detaches from the compound, leaving a polar ion.
- This ion binds to proteinaceous exudates in the upper GIT, forming a chemical barrier over ulcer sites
- Prevents further erosion from acid, pepsin and bile salts
What are the pharmacokinetics of anti-ulcers?
- Excreted in urine and faeces
