Drug Actions

Sugammadex, which selectively chelates rocuronium and other aminosteroid NMBA
Mannitol, which exerts an osmotic effect that induces diuresis and draws fluid from the interstitium
Activated charcoal, which has a high surface area to mass ratio and binds ingested poisons
Antacids, which neutralise gastric acid
Chelating agents such as penicillamine (copper) and dicobalt edetate (cyanide, sodium nitroprusside), which remove toxic chemicals from the body

Enzymes are biological catalysts - they speed up a reaction without themselves being used up
They are often highly specific to a given substrate, and their function is dependent to an extent on local pH and temperature

Most drugs that interact with enzymes are inhibitors
Enzyme inhibition can increase the concentration of a substrate normally metabolised by the enzyme e.g. anticholinesterases increasing acetylcholine concentration at the NMJ
Or conversely inhibition can reduce the concentration of the product of the enzymatic reaction e.g. ACE-inhibitors inhibit the catalysis of angiotensin I to angiotensin II conversion

Voltage-gated ion channels are involved in the conduction of action potentials/impulses in excitable tissue such as muscle and nerves
Examples of drugs that bind voltage-gate ion channels to produce a therapeutic effect include:

Local anaesthetics, which bind the intracellular portion of Na⁺ channels in nerve membranes
Anticonvulsants, which bind Na⁺ channels in the brain
Calcium channel blockers, which bind ion channels in vascular smooth muscle
Anti-arrhythmic agents, which block a variety of myocardial ion channels