Neuro Med 2

Drug Interactions and Efficacy

• Enhancing Drug Effectiveness

  • MAOIs (Monoamine Oxidase Inhibitors) enhance the efficacy of certain medications.

  • Selegiline is specifically used in the treatment of Parkinson's disease, often in combination with carbidopa and levodopa to enhance therapeutic effects.

Evaluating Medication Effectiveness

• Assessment of Drug Efficacy

  • Key indicators of medication effectiveness include improvement in spontaneous movement, indicative of reduced bradykinesia (slow movement) associated with conditions such as Parkinson's disease.

  • Patient reports like "My husband can walk around the yard" signify positive responses to treatment.

  • An increase in ambulation (ability to walk) reflects effectiveness and is considered an important measure in evaluating patient progress.

Anticholinergics: Overview and Function

• Examples and Applications

  • Medications such as benztropine and atropine serve multiple purposes, including increasing heart rate and reducing secretions, particularly in cholinergic crises.

  • Memory Trick: Anticholinergics lead to dryness: "No see, no pee, no spit, no poop."

  • Cholinergic medications increase secretions, referred to as "stigmines."

• Clinical Use Cases

  • Tropine medications are commonly used to manage tremors associated with Parkinson's disease and extrapyramidal side effects from antipsychotic medications.

  • Mechanism of action: Anticholinergics inhibit acetylcholine activity, which results in reduced secretions and tremors.

  • They treat symptoms such as bradykinesia and dystonia, which are abnormal movements of facial and neck muscles.

  • Important Note: Tropine medications do not address psychotic symptoms, such as delusions.

• Contraindications

  • Anticholinergic medications should not be given to patients who are already experiencing dryness or fluid retention, as it can exacerbate these conditions.

  • Atropine is contraindicated in patients with acute glaucoma and should not be administered to patients with Benign Prostatic Hyperplasia (BPH) or urinary retention due to the risk of worsening these conditions.

Mannitol: Indications and Side Effects

• Usage

  • Mannitol is indicated to decrease cerebral edema and intracranial pressure (ICP), particularly indicated for head injuries and conditions like meningitis.

  • It is also used for increased ocular pressure during glaucoma emergencies.

  • Memory Trick: MANITOL correlates with ICP reduction and patient assessment every hour.

• Pharmacological Considerations

  • Mannitol must be administered intravenously (IV); it cannot be given orally (PO).

  • One major side effect is fluid retention, beginning approximately 30 to 60 minutes post-administration, leading to signs of heart failure like peripheral and pulmonary edema.

  • Although it is a diuretic, its mechanism can paradoxically cause fluid overload due to the transfer of fluid from cells to the bloodstream, thus increasing blood volume.

Neuromuscular Blocking Agents

• Classes and Examples

  • Key neuromuscular blockers include succinylcholine, pancuronium, and cystacurium, with a notable emphasis on succinylcholine due to its frequent mention in exam reviews.

• Indications for Use

  • These medications are administered for muscle paralysis prior to intubation, facilitating mechanical ventilation, particularly in emergency situations or in the setting of general anesthesia.

  • It is crucial to understand that while these agents paralyze the body, they do not provide sedation, necessitating concurrent sedative administration to manage patient comfort during procedures.

• Risks and Adverse Effects

  • One significant risk associated with neuromuscular blockers is respiratory arrest due to diaphragm paralysis.

  • Patients remain conscious and can experience pain; therefore, sedation (e.g., midazolam) must precede administration of neuromuscular blockers to prevent discomfort.

• Malignant Hyperthermia

  • A severe adverse reaction to general anesthesia or succinylcholine characterized by muscle rigidity and hyperthermia (elevated body temperature).

  • The physiological explanation involves the release of calcium from muscle stores upon anesthetic administration, leading to increased metabolic demands and temperature control failure.

  • Mnemonic: MH - M for Muscle Rigidity and H for Hot (temperatures).

  • Immediate Intervention Protocol: Notify healthcare provider, administer dantrolene (a muscle relaxant), followed by supplemental oxygen and cooling measures to manage elevated temperatures.

• Risk Factors for Malignant Hyperthermia

  • Prior reactions to general anesthesia is a critical indicator when evaluating patient risk.

  • Family history of significant reactions to anesthesia raises concern for individual patient susceptibility.

  • Individuals with a history of alcohol use disorders are also considered high-risk for developing malignant hyperthermia during anesthetic procedures.