Activated charcoal

Mechanism of Action:

Highly absorbent carbon obtained by heating granulated charcoal to exhaust contained gases, resulting in a highly porous form with a very large surface area. It is used as an antidote to certain poisons. Reduces absorption of ingested poison, non-specific binding of the ingested poison in the gastrointestinal tract.

 

Flumazenil

UNDER REVIEW (September 2016)

Mechanism of Action:

Flumazenil is a benzodiazepine antagonist, used as an antidote in the treatment of benzodiazepine overdose. It reverses the effects of benzodiazepines by competitive inhibition of benzodiazepine receptors: interacts with the GABA(A) receptor to attenuate the effects of the inhibitory neurotransmitter GABA.

Lecture and CAL materials:

  • Lecture: Drugs affecting mood and cognition

Naloxone

Mechanism of Action:

Naloxone is a mu (μ)-opioid receptor competitive antagonist, and also has an antagonist action with a lower affinity, at κ- and δ-opioid receptors. It blocks the action of both exogenous opioids (e.g. morphine, diamorphine) and endogenous opioids on opioid receptors in the central nervous system. Opioid receptors are G-protein-coupled receptors and inhibit adenylate cyclase. They cause hyperpolarisation (by opening potassium channels causing K+ to move out of cells) and prevent transmitter release (by blocking calcium channels).

Naloxone is a derivative of the opioid oxymorphone, with the substitution of the N-methyl group with an allyl (prop-2-enyl) group to give N-allyl oxymorphone.

Indications

  • Reversal of opiate toxicity

Lecture and CAL materials: (under review)

  • Lecture: Pain and Analgesia (Lecture 2): Analgesics and other drugs used to treat pain
  • CAL: G Proteins

Acetylcysteine

UNDER REVIEW (April 2017)

Mechanism of Action:

NAC is a glutathione precursor that, unlike glutathione, has the potential to cross cell membranes and enter hepatocytes where it restores glutathione (GSH). GSH is necessary for the conversion of the toxic metabolite of paracetamol, NAPQI, to unreactive metabolites. When it is exhausted the toxix metabolites destroy the liver cells. Thus NAC is used to protect the liver from damage in paracetamol overdose. NAC also breaks disulphide bonds that holds mucus glycoproteins together (mucolytic).

Lecture and CAL materials:

  • Lecture: Drugs affecting the respiratory system