Belladonna

Oral
Smooth muscle spasms

Topical/Cutaneous
Musculoskeletal pain

Glaucoma, bronchial asthma, prostatic hyperplasia, urinary retention, tachycardia, circulatory insufficiency, ulcerative colitis, pyloric stenosis. Application to face (topical). Pregnancy and lactation.

Significant: Hypersensitivity reactions (e.g. rash); local irritation (topical); dryness of oral mucosa, constipation, acceleration of heart function, accommodation disorder (long-term use).
Eye disorders: Pupil paralysis, increased intraocular pressure.
Gastrointestinal disorders: Constipation.
Psychiatric disorders: Depression, visual hallucinations.
Skin and subcutaneous tissue disorders: Dry skin, skin redness (topical).

This drug may cause accommodation disorders or visual hallucinations, if affected, do not drive or operate machinery. Avoid contact on broken, inflamed, sunburnt, cut or grazed skin (topical).

Symptoms: Reduced sweat and salivary secretions, double vision, photophobia, skin redness, rash, increased body temp, mydriasis, tachycardia, palpitation, excitement, disorientation, hallucinations, speech disorders, delirium, seizures, coma, headache, hyperthermia. Management: Administer activated charcoal to reduce absorption. May give physostigmine or neostigmine as primary antidote; IV barbituric acid for delirium states. Artificial respiration may be required if necessary.

Enhanced effect with amantadine, quinidine, TCAs, MAOIs, antihistamines and neuroleptics. May antagonise effect of metoclopramide, cholinesterase inhibitors and parasympathomimetics. May reduce action of phenothiazine. May increase absorption of atenolol, digoxin, thiazide diuretics. May reduce absorption of cimetidine and levodopa.

Description:
Mechanism of Action: Belladonna contains several alkaloids derived from dried leaf and flowering tops of Atropa belladonna plant. It blocks muscarinic receptors in peripheral tissues such as gastrointestinal, urinary-tract and bronchial smooth muscles, and secretory glands, principally resulting from its atropine content. It also desensitises the nerve endings associated with the pain response when applied topically.
Synonym: atropa belladonna, deadly nightshade.
Pharmacokinetics:
Absorption: Well absorbed from the gastrointestinal tract.
Distribution: Crosses the placenta.
Metabolism: Hydrolysed in the liver to tropine and tropic acid.
Excretion: Via urine (approx 33% as unchanged drug); faeces, lesser extent. Elimination half-life: 2-3 hours.

Store below 25ºC. Protect from light and heat.
Any unused portion should be disposed of in accordance with local requirement.

Thuốc chống co thắt

Anon. Belladonna. AHFS Clinical Drug Information [online]. Bethesda, MD. American Society of Health-System Pharmacists, Inc. https://www.ahfscdi.com. Accessed 27/04/2018.

Belladonna Plaster (Cuxson Gerrard & Co. Ltd.). MHRA. https://products.mhra.gov.uk/. Accessed 27/04/2018.

Bellapan, 0.25 mg, Tablets (Farmapol, Poland). CSIOZ Poland. https://pub.rejestrymedyczne.csioz.gov.pl/. Accessed 27/04/2018.

Buckingham R (ed). Belladonna. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 27/04/2018.