Acetylcholinesterase inhibitors: drugs that block the action of the enzyme acetylcholinesterase that quickly breaks down the neurotransmitter acetylcholine.

ACP: advance care planning or advance care plan (a non-legally binding document that is reviewed and updated as a person’s views or situation change that must be taken into account when acting in a person’s best interests).

Adjuvant analgesics: drugs used to increase pain tolerance when conventional analgesics are non-effective.

ADRT: advance decision to refuse treatment.

Advance care planning: a documented discussion between a health and social care professional, a patient and those closest to them, that covers the patient’s wishes and preferences for their care and treatments in the future (what they want, what they don’t want and who will speak for them).

Advanced directives: instructions given by a person before they become mentally or physically incapacitated, that covers their future care and may include ADRT and power of attorney.

Anticholinergics: agents that block the passage of impulses through the parasympathetic nerves.

Antimuscarinics: an agent that counteracts the effects of muscarine or blocks the muscarinic receptors.

Apomorphine: a drug used for acute, intermittent treatment of hypomobility episodes in advanced parkinsonism.