This document discusses anticholinergic drugs, which block the effects of acetylcholine on cholinergic receptors. It classifies anticholinergic drugs as natural alkaloids like atropine and hyoscine, semisynthetic derivatives, or synthetic substitutes. The actions of these drugs include increasing heart rate, reducing secretions, relaxing smooth muscles, causing mydriasis and cycloplegia in the eyes, and stimulating or depressing the CNS. Common uses are as antispasmodics, mydriatics, pre-anesthetics, and for conditions like asthma, ulcers, and Parkinson's disease. Atropine substitutes have more selective actions and fewer side effects. Nursing considerations for

1. Anticholinergic
Drugs

2. INTRODUCTION
• Anticholinergic drugs are agents which block the effects
of acetylcholine on cholinergic receptors but
conventionally antimuscarinic drugs are referred to as
anticholinergic drugs.
• They are also called cholinergic blocking or
parasympatholytic drugs.
• Drugs that block the nicotinic receptors are ganglion
blockers and neuromuscular blockers.

3. • Anticholinergic drugs include atropine and related
drugs—atropine is the prototype.
• Atropine is obtained from the plant Atropa
belladonna. Atropine and scopolamine (hyoscine) are
the belladonna alkaloids.
• They compete with acetylcholine for muscarinic
receptors and block these receptors—they are
muscarinic antagonists.

4. CLASSIFICATION
Natural
alkaloids
Semisynthetic
derivatives
Synthetic
substitutes
Atropine, hyoscine
(scopolamine
Homatropine,
ipratropium bromide
Mydriatics(Eucatropine)
Antispasmodic-antisecretory
agentsPropantheline,
Antiparkinsonian agents
Benzhexol

5. Actions of anticholinergic drug
• The actions of atropine and scopolamine are similar
except that atropine is a CNS stimulant while
scopolamine is a CNS depressant and causes
sedation.
1. CVS—Atropine increases heart rate. In large doses,
vasodilation and hypotension occurs.

6. Actions of anticholinergic drug
2. Secretions—Atropine reduces all secretions except
milk. Lacrimal, salivary, nasopharyngeal,
tracheobronchial and gastric secretions are
decreased.
• Decreased salivation results in dry mouth and
difficulty in swallowing—it is an antisialogogue.
Sweating is also reduced

7. Actions of anticholinergic drug
3. Smooth muscle
• GIT – ↓ tone and motility and relieves spasm →may
result in constipation.
• Biliary tract – smooth muscles are relaxed; biliary
spasm is relieved.
• Bronchi – atropine causes bronchodilatation.
• Urinary bladder – relaxes ureter and urinary bladder
and may cause urinary retention particularly in the
elderly men because they may be having prostatic
hypertrophy.

8. Actions of anticholinergic drug
4. Eye—On local instillation, atropine produces
mydriasis by blocking the muscarinic receptors in the
sphincter pupillae.
• The ciliary muscle is paralysed resulting in cycloplegia
or paralysis of accommodation.
• Because of mydriasis, the iris may block the drainage
of aqueous humor—IOP increases and may
precipitate glaucoma in some patients.

9. Actions of anticholinergic drug
5. CNS—In higher doses atropine stimulates the CNS
resulting in restlessness, disorientation,
hallucinations and delirium. In contrast, scopolamine
produces sedation and drowsiness.

10. Pharmacokinetics
• Atropine and hyoscine are well-absorbed,
cross the BBB and are metabolised in the liver.

11. Adverse effects
Use of anticholinergic agents may result to these adverse
effects:
• CNS: blurred vision, pupil dilation, photophobia,
cycloplegia, increased intraocular pressure, weakness,
dizziness, insomnia
• CV: tachycardia, palpitation
• GI: dry mouth, altered taste perception, nausea,
heartburn, constipation
• GU: urinary hesitancy and retention, heat prostration

12. Uses of Belladonna Alkaloids
1. As antispasmodic
• In diarrhoea and dysentery, atropine relieves colic
and abdominal pain.
• In renal and biliary colic—atropine is used with
morphine because atropine partly overcomes spasm
of the sphincter of Oddi.
• Nocturnal enuresis in children and in paraplegia
atropine reduces urinary frequency.

13. Use
2. As mydriatric and cycloplegic
• Diagnostic for testing error of refraction and
fundoscopic examination of the eye.
• Therapeutic To provide rest to the iris in iritis,
iridocyclitis, keratitis and after partial iridectomy.
• Mydriatics are used alternately with miotics to break
adhesions between the iris and the lens - both for
the treatment and prevention of adhesion formation.

14. Use
3. As pre-anaesthetic medication When administered
30 min before anaesthesia, atropine reduces salivary
and respiratory secretions. This will prevent the
development of laryngospasm. It also prevents
bradycardia during surgery. Its bronchodilator action
is of additional value.
• Glycopyrrolate an atropine substitute, is most
commonly used for this purpose

15. Use
4. In organophosphorus poisoning Atropine is life saving
in OP poisoning and is also useful in mushroom
poisoning.
5. In bronchial asthma, peptic ulcer and parkinsonism
Atropine derivatives are preferred over atropine

16. Use
6. Motion sickness Hyoscine given 30 minutes before
the journey prevents travelling sickness. Transdermal
hyoscine patches are available to be applied behind
the ear for a prolonged action
7. Hyoscine can also be used during labour to produce
sedation and amnesia.

17. Drug interactions
• When anticholinergics are given with other drugs
that also have anticholinergic property like
antihistaminics, phenothiazines, tricyclic
antidepressants

18. ATROPINE SUBSTITUTES
• Belladonna alkaloids produce a wide range of effects,
most of which are of therapeutic value.
• But these can also result in various side effects since
they lack selectivity.
• Hence several semisynthetic and synthetic
derivatives have been introduced some of which
have selective actions

19. • Mydriasis and cycloplegia produced by atropine last
for 7–10 days. The derivatives have shorter action
(6–24 hrs), tropicamide being the shortest acting.
• Some can selectively produce either prominent
mydriasis or cycloplegia.

20. • Antispasmodics or spasmolytics are used to relieve
spasms of the gastrointestinal tract, biliary tract,
ureter and uterus. They are also found to be useful in
irritable bowel syndrome. Some of them in addition,
reduce gastrointestinal motility.

21. Atropine substitutes
Indications Derivatives
1. On the eye – mydriatics
and cycloplegics
Homatropine, eucatropine, cyclopentolate,
tropicamide
2. As antispasmodics Propantheline, methantheline, dicyclomine,
flavoxate hydrochloride, oxybutynin
chloride, oxyphenonium, glycopyrrolate,
clidinium
3. Peptic Ulcer Pirenzepine, telenzepine
4. Bronchial asthma Ipratropium, tiotropium
5. Preanaesthetic
medication
Glycopyrrolate
6. Urinary disorders Oxybutynin, tolterodine, propiverine,
dicyclomine
7. Antiparkinsonian drugs Benzhexol, benztropine, trihexyphenidyl.

22. • Pirenzepine and telenzepine are selective M1 blockers which
inhibit gastric secretion at doses that do not affect other
functions.
• Pirenzepine also does not cross the BBB – hence has no CNS
effects. They are tried in peptic ulcer.
• When used in bronchial asthma, atropine thickens the
bronchial secretions and interferes with the movement of
cilia, thus favouring formation of mucus plugs.

23. • Ipratropium bromide is a bronchodilator that does
not affect mucociliary activity.
• When given as inhalation it acts only on the airways
and does not produce any significant systemic effects
because it is poorly absorbed.

24. • Glycopyrrolat is an antisialogogue (reduces salivary
secretions). It is e a quaternary amine – does not cross the
BBB – therefore no effects on the CNS. It is given IM as
preanaesthetic medication and in dental practice when it is
necessary to reduce salivary secretions.
• Benztropine, benzhexol and trihexyphenidyl are the
derivatives used in drug induced parkinsonism.

25. • Urinary disorders – atropine substitutes are used to
reduce urinary urgency and frequency to relieve
bladder spasm and improve bladder capacity in
urinary disorders and following urologic surgeries.
They are also tried in nocturnal enuresis in children.

26. Contraindications and Cautions
The following are contraindications and cautions for the use
of anticholinergics:
• Allergy to any component of the drug. To prevent
hypersensitivity reaction
• Glaucoma. Can be exacerbated by blockade of PNS.
• Intestinal atony, paralytic ileus, GI obstruction. Can be
exacerbated with further slowing of GI activity.
• Pregnancy. Potential adverse effects on the fetus.

27. Nursing Considerations
Here are important nursing considerations when administering
anticholinergics:
Nursing Assessment
These are the important things the nurse should include in
conducting assessment, history taking, and examination:
• Assess for contraindications or cautions (e.g., history
of allergy to drug, GI obstruction, hepatorenal dysfunction,
etc.) to avoid adverse effects.
• Establish baseline physical assessment to monitor for any
potential adverse effects.

28. • Assess neurological status (e.g., orientation, affect, reflexes)
to evaluate any CNS effects.
• Assess abdomen (e.g., bowel sounds, bowel
and bladder patterns, urinary output) to evaluate for GI and
GU adverse effects.
• Monitor laboratory test results to determine need for possible
dose adjustments and to identify potential toxicity.

29. • Ensure proper administration of the drug to ensure effective
use and decrease the risk of adverse effects.
• Monitor patient response (e.g., blood pressure, ECG, urine
output) for changes that may indicate need to adjust dose.
• Provide comfort measures (e.g., sugarless lozenges, lighting
control, small and frequent meals) to help patient cope with
drug effects.
• Provide patient education about drug effects and warning
signs to report to enhance knowledge about drug therapy and
promote compliance.