Healthcare Professionals - Learn About Transdermal Verapamil 15% Gel For Fibrotic Tissue Disorders

Side Effects

The most common side effect reported with Transdermal Verapamil 15% Gel, affecting 3-5% of Peyronie's disease patients, is varying degrees of skin irritation. Some patients using the medication for the first time may experience mild itching/irritation during the first few days of treatment. This is normal and usually resolves within 3-4 days. Other patients may experience more severe contact dermatitis, including itching, burning, redness, or swelling. More persistent or severe irritation can usually be treated with topical corticosteroids. Based on the individual symptoms, PDLabs will work with the patient and prescribing physician to determine the best course of treatment to resolve irritation. This side effect is not seen in plantar fibromatosis or Dupuytren's disease patients.


A PDLabs pharmacist reviews all medications and supplements taken by a patient before filling a prescription and informs the patient if there is risk of adverse drug reactions. The pharmacist also consults with the patients' cardiologist or other specialist regarding any safety issues involved with using verapamil if the patient has a history of questionable medical conditions.

Drugs & Supplements That May Be
Contraindicated or May Interfere With Treatment Results

Beta Adrenergic Blocking Agents (Beta Blockers)

Commonly used to treat hypertension and certain arrhythmias. This class of drugs, as noted in the Physician's Desk Reference, has been reported to cause tissue fibrosis. In addition, there are many references in published literature indicating a link between beta blockers and Peyronie's disease. These drugs may also hinder the effectiveness of Transdermal Verapamil 15% Gel. Patients placed on an alternative therapy for hypertension such as a calcium channel blocker or ACE Inhibitor may respond more favorably to Transdermal Verapamil 15% Gel.

Statins (simvastatin, atorvastatin, and lovastatin)

Verapamil taken orally may interfere with the metabolism of these drugs, resulting in higher blood levels due to delayed drug metabolism and elimination. This can lead to an increased likelihood of experiencing muscle aches and/or pains and rhabdomyolysis. This is a possible side effect that occurs with statin therapy alone, but may be enhanced by using oral verapamil. Transdermal Verapamil 15% Gel is formulated to have minimal systemic absorbtion; however, the patient should be advised of this possible adverse effect.

Tetracycline, Doxycycline, and Minocycline

These medications can hinder or inhibit the production of collagenase, thereby interfering with the mechanism of action necessary to remodel the lesion.

Anti-Seizure Medications (phenytoin, phenobarbital, and primidone)

Connective tissue disorders have been listed as possible side effects of these drugs.


Patients taking digoxin/cyclosporin should have these drug levels monitored on a regular basis while using Transdermal Verapamil 15% Gel. Verapamil taken orally may decrease the metabolism and clearance rate of these drugs, possibly resulting in toxic levels. Transdermal Verapamil 15% Gel is formulated to have minimal systemic absorbtion; however, the patient should be advised of this possible adverse effect.


Tobacco use impedes the skin's ability to absorb topically applied medication by lowering the skin's temperature. Recently published studies have also implicated nicotine in the delay of wound healing.

Glucosamine/Chondroitin Compounds

Chondroitin sulfate is a glycosaminoglycan (GAG). It combines with keratan sulfate, dermatan sulfate and heparan sulfate, and accumulates in cartilage on cell surfaces and matrixes; it is widespread in connective tissues, and is found in the secretory vesicles in white blood cells and on fibroblast and epithelial cell surfaces. It provides mechanical support, helps to package and store secretory molecules, and functions in cell adhesion*. It also binds to Transforming Growth Factor Beta which, in excess, has been associated with Peyronie's disease. Chondroitin compounds also bind to Fibroblast Growth Factor (FGF) and to Type I collagen fibrils. PDLabs recommends patients discontinue this supplement when treating fibrotic tissue disorders with Transdermal Verapamil 15% Gel.

Large Daily Doses of Vitamin C (Ascorbic Acid)

Excess ascorbic acid intake can promote excess collagen production since it is essential for the conversion of proline to hydroxyproline in the collagen production process. PDLabs recommends not taking more than 400mg of Vitamin C daily while being treated with Transdermal Verapamil 15% Gel.

*Alberts, B., Bray, D., Lewis, J., Raff, M., Roberts, K., Watson, J. : Molecular Biology of the Cell, Third Edition, 1994, CH 19: 978-995