The Risks Associated With Counterfeit PDE-5 Inhibitors
The health risks associated with the use of counterfeit PDE-5 inhibitors fall into 2 main categories: risks arising from the unsupervised use of PDE-5 inhibitors, and risks from other active substances and impurities that may be among the ingredients of counterfeit drugs. In many, if not most, cases, men who take counterfeit medications may be exposed to both types of risk.
Risks that fall into the first category -- those due to the unsupervised use of PDE-5 inhibitors -- are the easier of the two to contend with because there is extensive data available on the side effects of this class of drug. Although contraindications to the use of PDE-5 inhibitors are clearly listed in the package inserts, unlicensed online pharmacies usually include only the most basic instructions about dosing and rarely make any attempt to ensure that the patient is aware of contraindications. It may therefore be assumed that a man who has obtained a counterfeit PDE-5 inhibitor will not know of the precautions and contraindications to their use.
As many men who use PDE-5 inhibitors may, based on age alone, have some form of cardiovascular disease, such as angina treated with nitroglycerin, and/or benign prostatic hypertrophy treated with alpha-blockers (prazosin, doxazosin, terazosin, tamsulosin, alfuzosin), there is the real potential for drug interactions. Similarly, many other common medications may inhibit the metabolism of a PDE-5 inhibitor and result in adverse effects. Cytochrome inhibitors including itraconazole, ketoconazole, and erythromycin may require adjusting the dosage of the PDE-5 inhibitor. In general, use of cytochrome inhibitors necessitates reduction of the dose of PDE-5 inhibitors to the lowest effective dose in a 24-hour period. Additionally, patients receiving ritonavir should not exceed 25 mg of sildenafil in 48 hours because of the impact of ritonavir on serum concentration duration in healthy adults.
Overall, patients with significant cardiovascular disease and/or those taking medications that interact with the mechanism of action or the metabolism of PDE-5 inhibitors are at the highest risk for morbidity or mortality following intentional or unintentional consumption of a PDE-5 inhibitor.
As mentioned above, it is widely documented that there are variable doses of active ingredients in many of these counterfeit medications. This variability, as well as mislabeling, may lead to accidental overdose as the patient may not be able to accurately determine the actual dose he has consumed. One possible scenario is that a patient who takes a counterfeit PDE-5 inhibitor containing a lower dose of the active ingredient than indicated on the label may adjust the dosage upwards to get an effect. If the same patient consequently receives a full-strength drug, he may inadvertently overdose by taking the same dose as he had taken of the weaker counterfeit version. Although overdoses of PDE-5 inhibitors generally have no untoward consequences in younger study subjects, the results in patients of advanced age and with a number of vascular comorbidities can be of consequence.
In addition to dose variability, substituted and other undisclosed ingredients may result in significant morbidity or mortality. Ingredients used as fillers to add bulk to the pill may vary in composition and may include substances that cause allergies. It is, of course, impossible to anticipate all of the adverse events that may occur as the result of every possible ingredient that may be found in a counterfeit medication. When treating a patient that you suspect may have ingested a counterfeit medication for erectile dysfunction (or for any other indication), it is therefore important to try to obtain samples of the counterfeit medication in the event that laboratory analysis may be needed. Keep in mind, however, that a man who has taken a counterfeit drug may be reluctant to admit to it. He may be embarrassed not only to reveal that he suffers from erectile dysfunction, but may also fear that he has broken a law in obtaining the counterfeit drug.
Medscape Urology © 2007 Medscape
Cite this: The Illicit Sale of Medications for the Treatment of Erectile Dysfunction - Medscape - Dec 11, 2007.