Can BPH Be Treated With Scopolamine? What Men With Enlarged Prostate Should Know

Hello,

There are two separate questions here: whether scopolamine can treat BPH, and whether a man with BPH can ever safely use scopolamine for another reason. The answers are different.

What Kind of Drug Is Scopolamine?

Scopolamine is not a muscarinic agonist. The old answer had the drug class reversed.

Scopolamine is an antimuscarinic, also called an anticholinergic. It blocks the effects of acetylcholine at muscarinic receptors.

Transdermal scopolamine is FDA approved in adults for prevention of:

• motion-sickness nausea and vomiting; and
• postoperative nausea and vomiting associated with anesthesia, opioid analgesia or surgery.

It is not approved as a treatment for benign prostatic hyperplasia.

Why Can Scopolamine Cause Urinary Problems?

The bladder’s detrusor muscle normally contracts partly through muscarinic signaling. By blocking that signaling, anticholinergic medicines can make bladder contraction less effective.

In someone who already has difficulty passing urine because of prostate enlargement or bladder-neck obstruction, this can make emptying worse and occasionally contribute to urinary retention.

The current FDA prescribing information for transdermal scopolamine specifically warns that, because of its anticholinergic effects, it can cause urinary retention. It recommends closer monitoring in patients with impeded urine flow, including men with prostate disease or bladder-neck obstruction, and advises discontinuation if difficulty urinating develops.

Is BPH an Absolute Contraindication to Scopolamine?

No. That distinction is important.

The FDA label lists angle-closure glaucoma and hypersensitivity to scopolamine or related belladonna alkaloids as formal contraindications. Prostate disease is addressed under warnings and precautions because of the possibility of urinary retention.

Therefore, I would not tell a patient that BPH automatically means scopolamine can never be used. Instead, the prescribing clinician should consider:

• how severe the urinary symptoms are;
• whether there is a weak stream or incomplete emptying;
• the post-void residual urine volume;
• whether there has been previous urinary retention;
• other anticholinergic medicines being taken; and
• why scopolamine is needed.

Can Antimuscarinic Drugs Ever Be Used in Men With BPH?

Yes—and this is another major correction to the old article.

Men with BPH often have two broad types of lower urinary tract symptoms:

• voiding symptoms such as weak stream, hesitancy and straining; and
• storage symptoms such as urgency, frequency and urge incontinence.

For men whose main problem is persistent storage symptoms, urology guidelines allow carefully selected muscarinic receptor antagonists such as solifenacin or tolterodine, sometimes alone and sometimes with an alpha blocker.

The American Urological Association notes that anticholinergic agents may be offered to men with moderate-to-severe predominant storage symptoms, although post-void residual should be assessed because of the potential for worsening retention.

The European Association of Urology similarly recommends muscarinic receptor antagonists for men with moderate-to-severe storage symptoms, but advises against antimuscarinic overactive-bladder medicines when the post-void residual is greater than 150 mL.

What Medicines Are Actually Used for BPH?

The older article said there were only two drug groups. Modern treatment is broader.

See our full guide to BPH medications.

What If You Already Use Scopolamine?

If scopolamine was prescribed for motion sickness, surgery-related nausea or another legitimate reason, do not automatically stop a prescribed medicine solely because you have BPH.

Instead, tell the prescribing clinician that you have prostate enlargement or urinary symptoms—especially if you already have:

• a weak stream;
• difficulty starting urination;
• incomplete emptying;
• a high post-void residual;
• a history of urinary retention; or
• significant bladder-neck obstruction.

Your doctor can decide whether scopolamine is appropriate, whether another anti-nausea medicine would be preferable, or whether closer monitoring is sufficient.

When Should Scopolamine Be Stopped and Medical Help Sought?

Does Scopolamine Make the Prostate Grow?

No evidence supports that claim.

The old page stated that scopolamine stimulates muscarinic receptors and therefore stimulates prostate-cell growth. In reality, scopolamine blocks muscarinic receptors. Its urinary risk comes from reducing bladder contractility and potentially worsening emptying in a susceptible patient—not from enlarging the prostate.

Would Scopolamine Ever Be Chosen Specifically for BPH?

No.

If a man with BPH has urgency, frequency or urge leakage, a urologist might consider an antimuscarinic that has been studied for overactive-bladder symptoms, or a beta-3 agonist, after assessing post-void residual and the likelihood of obstruction.

Scopolamine itself would not be selected to treat the enlarged prostate or its lower urinary tract symptoms.