Exam Overview

• Focus on antibiotics and pain medications primarily.

• A couple of cholinergic meds included for the final exam.

• Important chapters: 20 & 21.

Nervous System Basics

• Parasympathetic Nervous System (PNS):

  • Function: Rest and digest (opposes sympathetic fight or flight).

  • Neurotransmitter: Acetylcholine (ACh).

  • Receptors:

    • Nicotinic: Respond to high doses; generally not the focus for most cholinergic medications.

    • Muscarinic: Main target for medications; affects smooth muscle, cardiac muscles, and glands.

Mechanisms of Action

• Effects of Acetylcholine:

  • Cardiovascular:

    • Increased vasodilation (wider blood vessels).

    • Decreased heart rate and blood pressure.

    • Potential eye effects: Miosis (pupil constriction).

  • Respiratory:

    • Bronchoconstriction and increased secretions, relevant for patients at risk for mucus accumulation.

  • GI and Urinary:

    • Increased GI motility and gastric secretions → more frequent peeing and pooping.

  • Ophthalmic:

    • Reduces intraocular pressure – beneficial for glaucoma patients.

  • Glandular:

    • Increases salivation and sweating.

Cholinergic Medications

• Examples:

  • Bethanechol:

    • Increases bladder tone and motility; particularly used post-surgery for bladder issues.

    • Contraindications: hypersensitivity, urinary obstruction, asthma, coronary artery disease.

  • Indirect-acting cholinergics:

    • Used in conditions like myasthenia gravis and Alzheimer’s disease (e.g., Donepezil).

Therapeutic Effects of Cholinergic Drugs

• Achieves goals by mimicking acetylcholine to restore balance in body functions.

• Outcomes for patients include:

  • Effective urination and bowel movements for those with urinary retention or gastroparesis.

  • For Alzheimer’s patients, potential improvements in mood and cognitive functions (slow progression of symptoms).

Adverse Effects and Toxicity

• Signs of Overdose:

  • Syncope, hypotension, GI upset, seizures, increased salivation, lacrimation, urination, diarrhea, gastrointestinal cramps (SLUDGE).

• Cholinergic Crisis:

  • Severe overdose can lead to cholinergic crisis requiring urgent treatment (Atropine as antidote).

Anticholinergic Medications

• Definition: Block the actions of acetylcholine.

• Effects:

  • Increase heart rate in high doses;

  • Decrease secretions from glands (dry mouth, decreased sweating);

  • Dilation of pupils (blind as a bat);

  • GI slow-down – urinary retention.

• Common medications: Atropine and Oxybutynin.

Use Cases for Anticholinergic Medications

• Treatment of bradycardia, IBS, and bronchial spasms (asthma, COPD).

• Caution in patients with glaucoma or those experiencing urinary retention.

Important Points to Remember

• Dosage must be accurate; can cause serious side effects if mismanaged.

• Always monitor for therapeutic effects and side effects; interventions needed for overdose should be quick and effective (e.g., Atropine for cholinergic crisis).

• Patients should avoid dehydration and heat exposure when on anticholinergic medications due to risk of heat stroke.

Exam Preparation

• Review chapters thoroughly, focusing on both cholinergic and anticholinergic drugs and their interactions particularly with antibiotics and pain medications - these considerations are crucial for understanding patient care requirements.

• Important mnemonics:

  • SLUDGE for cholinergic crisis

  • Hot as a hare, dry as a bone, blind as a bat, etc. for anticholinergic effects.

Review and Q&A

• Engage in active dialogue with peers to clarify concepts and relate them to patient care scenarios.

• Utilize textbook questions to solidify understanding and apply knowledge effectively for the exam.