A client is receiving bethanechol (Urecholine). The nurse realizes that the action of this drug is to treat which condition?

Atenolol (Tenormin) is a cardioselective beta-1 blocker prescribed for hypertension, angina, and cardiac arrhythmias. Nurses must evaluate potential drug interactions that could reduce atenolol’s effectiveness or amplify its adverse effects, especially those that affect heart rate, blood pressure, or renal perfusion.

Rationale for correct answers:

2. An NSAID, such as aspirin – NSAIDs can reduce the antihypertensive effects of beta-blockers like atenolol by inhibiting renal prostaglandins, potentially increasing blood pressure.

3. Atropine, an anticholinergic – Atropine increases heart rate by blocking parasympathetic input, which may counteract atenolol’s beta-blocking effect, potentially complicating heart rate control.

Rationale for incorrect answers:

1. Ginseng supplement – While ginseng may have mild cardiovascular effects, it has not been shown to consistently interfere with atenolol. It is not a well-documented interaction.

4. Haloperidol (Haldol) – Although both drugs may prolong the QT interval, there is no direct, frequent interaction reported between haloperidol and atenolol affecting the drug's main mechanism.

5. Methyldopa (Aldomet) – Both methyldopa and atenolol lower blood pressure, but they are sometimes used together. Their additive effect is monitored, but this is not considered a strong or dangerous interaction.

Take-home points:

• NSAIDs can blunt the antihypertensive effect of beta-blockers like atenolol.
• Atropine may reduce atenolol's therapeutic effect by increasing heart rate.
• Always evaluate over-the-counter medications or supplements for potential cardiovascular interactions.

Benztropine (Cogentin) is an anticholinergic medication commonly used to manage extrapyramidal symptoms in Parkinson’s disease or from antipsychotic use. Like other anticholinergics, it reduces parasympathetic activity, which can lead to various systemic effects—particularly those involving the gastrointestinal tract.

Rationale for correct answer:

2. Constipation
Constipation is a frequent side effect of anticholinergic medications due to slowed peristalsis and reduced secretions. Clients should be educated on increasing fluid and fiber intake and the possible need for stool softeners.

Rationale for incorrect answer:

1. Heartburn
Benztropine decreases gastric motility and acid secretion, which may actually reduce the risk of heartburn rather than cause it. This is not considered a common adverse effect.

3. Hypothermia
Benztropine may impair heat dissipation and lead to hyperthermia, not hypothermia, especially in hot environments due to inhibited sweating.

4. Increased gastric motility
This medication reduces gastric and intestinal motility, not increases it. Slowed GI transit is why constipation becomes a primary concern during therapy.

Take-home points:

• Constipation is a common and expected side effect of benztropine due to reduced GI motility.
• Client education should include preventive strategies such as hydration, dietary fiber, and physical activity.
• Anticholinergics may also reduce the ability to sweat, increasing the risk of heat-related complications.