Question

An 86 year old lady presented with severe constipation. She was a known hypertensive on medications for 10 years. In clinic, her BP was 157/98 mm Hg with a heart rate of 58/min. On taking her BP in the supine position it was found to be 90/60 mm Hg. She had a recent history of depression. She is taking atenolol, thiazide, imipramine, haloperidol and docusate. What will be the next best step in the management?

• A. Change atenolol and thiazide to a calcium channel blocker and ACE inhibitor and add bisacodyl for constipation
• B. Change imipramine and haloperidol to fluoxetine and risperidone and add bisacodyl for constipation
• C. Only add bisacodyl for constipation and continue rest of the medications
• D. Discontinue all her medications and start her on steroids

Hint:

Find the anticholinergic and alpha blocking culprits causing constipation and postural hypotension.

Answer 1

The Correct Option is B

Step 1: The key problems are severe constipation and a large postural drop in blood pressure (157/98 standing falling to 90/60 supine pattern, that is marked orthostatic instability) in an elderly woman.

Step 2: Imipramine is a tricyclic antidepressant. It causes postural hypotension through alpha adrenergic blockade and has strong anticholinergic effects that worsen constipation. Haloperidol adds further anticholinergic burden. These two drugs are the main offenders.

Step 3: The correct move is to stop imipramine and switch to an SSRI such as fluoxetine for depression, and to replace haloperidol with the atypical antipsychotic risperidone, which has a lower anticholinergic load. A laxative like bisacodyl is added for the existing constipation.

Step 4: Why the others are wrong: changing the antihypertensives alone (option a) ignores the drugs actually driving the anticholinergic constipation and hypotension; only adding a laxative (option c) treats a symptom while leaving the offending drugs in place; and stopping everything and starting steroids (option d) is unjustified and dangerous. So the answer is option b.