US Pharm
. 2010;35(6):8-15. 

Nonprescription products and devices carry numerous warnings, precautions, and contraindications. One is a prohibition against use by patients with diabetes. Pharmacists must be aware of which products carry this warning when counseling patients with diabetes. Further, they should be able to suggest products that are safe or, when self-treatment of the condition might be dangerous, recommend that the patient visit a physician. 

Nasal Congestion

Nasal congestion is a prominent symptom of the common cold, allergic rhinitis, and other conditions. Nonprescription nasal decongestants carry a label that warns patients with diabetes against use unless they have spoken to a physician. The products have the ability to alter the often delicate balance between insulin and blood glucose by increasing blood glucose.1,2 However, there are several potential options when patients with diabetes have nasal congestion. 

The only two nonprescription oral nasal decongestants are phenylephrine and pseudoephedrine. Pseudoephedrine sales are limited to pharmacist-only (behind-the-counter) status.3 Although this move was made solely to limit the flow of pseudoephedrine to meth labs, it carried with it the advantage of offering pharmacists an opportunity to question all potential pseudoephedrine buyers about contraindicated conditions such as diabetes. Pharmacists can thereby instruct patients with diabetes not to use the ingredient unless a physician has advised them to do so. 

Most topical nasal decongestants also carry the warning against use by patients with diabetes, due to the possibility that some of the chemical might be absorbed and reach blood levels that would endanger their health. However, one nasal decongestant product is not required to carry the obligatory warnings. This is the nasal inhaler ingredient propylhexedrine (Benzedrex).4 It is not the optimal choice for patients with diabetes, as its use can result in rhinitis medicamentosa, a clinical condition in which the nasal turbinates actually become more congested as the product is used. Additionally, some patients are uncomfortable with inhalers, as they require the insertion of a tube into the nose. Finally, if several family members use the same inhaler, the viruses that cause the common cold might be transmitted between them. 

A better option for nasal congestion for patients with diabetes is a nonpharmacologic product that mechanically opens the nasal passages, typified by Breathe Right Nasal Strips.3 Before using the slender, plastic, adhesive-backed strip, patients should first remove any cosmetics or skin oils from the bridge of the nose, allowing it to dry. Then they can remove the paper from the back of the strip, exposing the adhesive. Bend the strip and apply it between the bridge and the tip of the nose, pressing the strip into place and rubbing it gently to ensure a tight seal. When the strip is released, it attempts to return to its preapplication state, thereby pulling the nostrils slightly open and allowing the patient to breathe more freely through the nostrils. 


Nonprescription products for asthma contain either ephedrine combined with guaifenesin (tablets) or epinephrine (inhalers). Both are poor choices for many reasons. For instance, current asthma guidelines do not recommend oral beta-agonists such as ephedrine for the treatment of asthma, recommending instead inhaled beta-agonists as superior options.5 Further, when an inhaled beta-agonist is considered for asthma, current medical practice suggests choosing a more selective beta-2 ingredient (e.g., albuterol, metaproterenol), as it is not as prone to produce beta-1 cardiac effects as the less selective molecules such as ephedrine and epinephrine. 

The guaifenesin in oral asthma products (e.g., Primatene) is an irrational ingredient. The etiology of asthma includes narrowing of the airways rather than impaired mucokinesis. It is difficult to envision any benefit from an expectorant in asthma, and nonprescription guaifenesin is not considered by the FDA to be safe or effective in asthma.5 While guaifenesin would probably not produce any adverse reactions in the asthmatic patient, its inclusion is puzzling. The best advice a pharmacist can give patients with diabetes who ask about nonprescription asthma products is to visit their primary care physician for a full medical evaluation and a more appropriate prescription product when or if indicated. 


Some hemorrhoid products (e.g., Preparation H Hemorrhoidal Ointment) include vasoconstrictors (e.g., phenylephrine) to decrease swelling. If the patient reads and follows all labeled directions for frequency of use, the possibility of absorbing the ingredient in sufficient amounts to cause a medically significant drop in blood pressure is remote.5 Nevertheless, the products carry a warning against use by patients with diabetes unless advised to do so by a physician. The pharmacist should recommend a vasoconstrictor-free hemorrhoidal product for patients with diabetes, such as Preparation H Anti-Itch Cream with Hydrocortisone or Tucks Hemorrhoidal Ointment. 

Vaginal Candidiasis

Products for vaginal candidiasis (fungal or yeast infection) carry a warning against use if the patient has certain serious medical causes for the symptoms, including diabetes. Diabetes is a major risk factor for vulvovaginal candidiasis, as it may be resistant to treatment.5-7 It is preferable to refer the female patient with candidiasis to her physician for a prescription product. 

Conditions Requiring Topical Heat

The patient with diabetes may wish to purchase a product to provide local heat (thermotherapy). There are several reasons why such a request might be made. The patient may wish to treat a minor injury, such as an ankle sprain, or a sports-related knee or back injury.5 The patient may also wish to treat an overuse syndrome, such as chondromalacia, an inflammation of the patella often seen in otherwise healthy young runners.8 Topical heat is usually suitable for overuse syndromes and is often used during the rehabilitation phase after an acute injury (e.g., after 48-72 hours have passed). Pharmacists should advise extreme caution in the use of thermotherapy in patients with diabetes. 

The FDA and the Consumer Product Safety Commission warned the public about the dangers of heating pads in 1995 and again in 2009.9,10 The warnings included the explanation that patients with diabetes may not be able to feel pain caused by a heating pad burn because of neuropathy. The CDC also warned patients with diabetes not to use heating pads, hot water bottles, or electric blankets to prevent burns to the feet.11 Since the pharmacist usually does not know the extent of the patient’s neuropathy, it is prudent to advise against use of thermotherapy. The manufacturer of therapeutic heat wraps (e.g., ThermaCare) also advises that patients consult with their physicians before using the product.12 


Warts may be successfully treated with salicylic acid, which is safe and effective in concentrations up to 17% in liquid dosage forms (e.g., collodions) or 40% in solid dosage forms (e.g., patches).5 However, all wart products containing salicylic acid warn against use by patients with diabetes. Salicylic acid is erosive to the stratum corneum, the basis for its use on warts. A patient with normal feeling in the feet may be able to perceive when the salicylic acid is causing damage and stop use. The patient with diabetic neuropathy affecting the feet or any area where a wart may be found might be unable to perceive damage and continue use. This could result in irreversible damage necessitating an amputation. Thus, the patient with diabetes who wishes to self-treat warts should be referred to his or her physician for an exploration of other options. 

Corns and Calluses

Corns and calluses are physiologic responses to sustained pressure and friction.5 Corns are limited to the feet, while calluses can occur at virtually any location on the body. Patients with diabetes may be more prone to experience corns and calluses than patients with normal sensation. Loss of sensation caused by neuropathy may cause patients to wear uncomfortable shoes longer, increasing the risk of blistering and eventual callus formation. The same risks apply to self-treatment as they do with warts, since the active ingredient of corn and callus products is also salicylic acid. Patients who wish to self-treat corns and calluses should also be referred to their medical practitioner. 

Nicotine Addiction

Some nicotine cessation products carry warnings against use by patients with diabetes. Nicotine gum (e.g., Nicorette) and nicotine lozenges (e.g., Commit) both warn diabetic patients against use, as these products can promote hyperinsulinemia, leading to insulin resistance.5 The pharmacist can recommend nicotine patches (e.g., NicoDerm CQ), as they do not carry this warning. 

Liquid and Powder Products

Manufacturers market a host of ingested, liquid nonprescription medications, from nausea remedies (e.g., Emetrol) to cough/cold medications and products for allergic rhinitis. They also market certain powdered products that contain sugar (e.g., some Metamucil products).13 The best advice is for the pharmacist to assist the patient in examining each label prior to sale to determine whether the product contains sucrose. This assistance can be crucial, as some patients with diabetes have compromised vision. Web sites may be helpful, such as the site warning patients with diabetes against use of Emetrol unless they are under the supervision of their physician.14 The pharmacist may be able to recommend an alternative, sugar-free product or a different dosage form (e.g., capsules or tablets), or might refer the patient to a prescriber. 

Dietary Supplements, Herbals, and Homeopathics

Numerous companies and Web sites offer dietary supplements, herbals, and homeopathic products that claim to help patients with diabetes control their condition. Entering the search term “cure type 1 diabetes supplements” into a Google search returns millions of hits. Examining these sites allows the concerned health care provider to see that patients are exposed to a plethora of unproven claims, such as that diabetes is treatable or curable with cinnamon, liquid ionic vanadium, Vitalzym (touted by a “naturopath”), Protocel, bitter melon, Gymnema sylvestre, and hundreds of other questionable and potentially dangerous remedies.15-17 It is vital that the pharmacist inform patients with diabetes that using these products is a needless and dangerous foray into a medically unrecognized world where hype is often mistaken for reality. 

What Products Can I Take?

There are numerous products that are safe for patients with diabetes, although you should read each label carefully. In general, products for constipation or diarrhea are safe for use, although you should check liquids and powders such as Metamucil to see if they contain sugar. If they do, search for a sugar-free product. Most internal analgesics (e.g., Tylenol, Aleve, Motrin IB) are also safe in diabetes. 

What Drug Interactions Are Important?

Some nonprescription products carry warnings against use if you are taking medications for your diabetes. These OTC products include bismuth subsalicylate (e.g., Pepto-Bismol) for upset stomach or diarrhea; alli for weight loss; aspirin; magnesium salicylate for back pain or headache; and migraine products containing acetaminophen, aspirin, and/or caffeine. 

Which Products Are Unsafe? What Are Safe Alternatives?

You should ask a physician before taking any oral nasal decongestant tablets, capsules, or liquids, as well as almost all nasal sprays, drops, inhalers, and cough/cold combinations containing a decongestant. A safe option is a nasal strip (e.g., Breathe Right), which gently pulls your nostrils open after it is applied to ease your breathing. 

Asthma products carry a warning against unsupervised use in patients with diabetes. Unfortunately, there is no safe nonprescription option, and a physician visit for control of the asthma is the safest choice. The same precaution applies to vaginal products for fungal infections. There is no safe option if you have diabetes, and you should seek medical care. 

Hemorrhoid products containing phenylephrine should not be used without a physician’s advice. In this case, there are safe nonprescription products that do not contain phenylephrine, but you must check the label closely to be sure you choose one of them. 

You must be extremely careful with products that supply heat to the body, such as heating pads, hot water bottles, and electric blankets. Some patients with diabetes do not have full feeling in parts of the body, such as the feet. They cannot feel the burn if the heating pad is set too high, and they could suffer a severe burn or even lose a limb. 

Nonprescription treatment of warts, corns, or calluses involves application of salicylic acid, which slowly erodes the skin to remove the problem. However, if the patient has diabetes, salicylic acid could produce an infection from the skin erosion and the patient could lose a limb. Do not use such devices as files, skin buffers, or razor blades, as they can also result in serious medical problems. There is no safe nonprescription product for corns, calluses, and warts for the patient with diabetes, and a physician visit is the best choice to prevent serious problems. 

Nicotine cessation gum and lozenges warn against use in diabetes. For the patient attempting smoking cessation, however, nicotine patches (e.g., NicoDerm CQ) are safe for those with diabetes when used as directed. 

Remember, if you have questions, Consult Your Pharmacist.


1. Cough, cold, allergy, bronchodilator, and antiasthmatic drug products for over-the-counter human use; tentative final monograph for over-the-counter nasal decongestant drug products. Fed Regist. 1985;50(10):2220-2241. 
2. Frequently asked questions. Tylenol Sinus Congestion & Pain Day/Night Pack. McNeil Consumer Healthcare. id=tylenol/sinus/ Accessed April 20, 2010.
3. Pray WS. Pseudoephedrine: stricter controls in the future? US Pharm. 2010;35(1):17-19. d/consult_your_pharmacist/c/ 18882/. Accessed May 14, 2010.
4. Final monograph for OTC nasal decongestant drug products; final rule. Fed Regist.  1994;59(162):43386-43412.
5. Pray WS. Nonprescription Product Therapeutics. 2nd ed. Baltimore, MD: Lippincott Williams & Wilkins; 2006.
6. Malazy OT, Shariat M, Heshmat R, et al. Vulvovaginal candidiasis and its related factors in diabetic women. Taiwan J Obstet Gynecol. 2007;46:399-404.
7. Anthony G, Saralaya V, Gopalkrishna BK, et al. Effect of phenotypic switching on expression of virulence factors by Candida albicans causing candidiasis in diabetic patients. Rev Iberoam Micol. 2009;26:202-205.
8. Chrondromalacia patella. MedlinePlus. Accessed April 20, 2010.
9. FDA/CPSC public health advisory: hazards associated with the use of electric heating pads. FDA/ 
Consumer Product Safety Commission. December 12, 1995. PublicHealthNotifications/UCM062624.pdf. Accessed April 20, 2010.
10. Questions and answers on HoMedics, Inc. heating pads and general heating pad safety. FDA. June 24, 2009. Accessed April 20, 2010.
11. Diabetes public health resource. Take charge of your diabetes. 9. Foot problems. Centers for Disease Control and Prevention. Accessed April 20, 2010.
12. ThermaCare HeatWraps. Frequently asked questions. Wyeth Consumer Healthcare. Accessed April 20, 2010.
13. Metamucil. Frequently asked questions. Procter & Gamble. Accessed April 20, 2010.
14. Emetrol. Directions. WellSpring Pharmaceutical Corporation. Accessed April 20, 2010.
15. Natural treatment for type I diabetes. Cancer Tutor. Accessed April 20, 2010.
16. Meshshringi (Gymnema sylvestre)—diabetes cure. Green Herbal Remedies. . Accessed April 20, 2010.
17. Karela. Herbal Cure India. Accessed April 20, 2010. 

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Feedback on Head Lice Column (March 2010) 

In his discussion of pediculicide resistance, Dr. Pray raises questions regarding the continued efficacy of Ovide (malathion) lotion 0.5%.1 As Dr. Pray notes, resistance to pyrethroid head lice products developed in the 1990s. In response to the emergence of resistant head lice, the CDC in 1999 specifically requested the reintroduction of prescription malathion.2 Subsequent, direct, clinical head-to-head studies in the United States have shown that malathion provides 97% to 98% cure rate, compared to 45% to 55% for a leading OTC pyrethroid product.3,4 An assessment of cholinesterase inhibition in patients receiving malathion showed no evidence of systemic absorption or effect.4 Dr. Pray also highlights the emergence of malathion resistance in Europe, particularly the UK. Nonetheless, the most recent published comparative study of head lice treatments, which included UK sites, continues to show that treatment with malathion lotion 0.5% provides approximately 90% efficacy even in patients with resistant lice.5 

Comparative clinical data represent the best approach to assess the efficacy of various head lice treatments. The absence of head-to-head clinical trial data makes it difficult to assess the potential efficacy of newer treatments such as Ulesfia (benzyl alcohol) in comparison to established treatments with documented, clinical trial comparative efficacy data. 

Just as a reminder, Ovide is indicated for the treatment of pediculosis capitis infestation of the scalp with head lice and their ova. The approved treatment regimen is an 8- to 12-hour application with a repeat treatment in 7 to 9 days only if live head lice are noted. Irritation to the skin and scalp is the most common adverse reaction. Accidental contact with the eyes can result in mild conjunctivitis. Ovide lotion is contraindicated for neonates and infants. Because this product contains isopropyl alcohol, it is flammable. Parents and patients should be instructed to keep away from heat sources (i.e., hair dryers, cigarettes) or open flame while the hair is wet. See the full Prescribing Information for complete safety information.6 

Howard Rutman, MD, Medical Affairs
Kate Shattuck, RPh, Pharmacy Policy
Taro Pharmaceuticals, U.S.A., Inc.
Hawthorne, New York
Taro Pharmaceuticals distributes Ovide (malathion) lotion 0.5% in the U.S.


1. Pray WS. Head lice: new approaches may help overcome pediculicide resistance. US Pharm. 2010;35(3):10-15.
2. Jackson EM. Medicis asked to reintroduce Ovide (malathion) lotion 0.5% for head lice. Cosmet Dermatol. 2000;13:43-44.
3. Meinking TL, Vicaria M, Eyerdam DH, et al. Efficacy of a reduced application time of Ovide lotion (0.5% malathion) compared to Nix creme rinse (1% permethrin) for the treatment of head lice. Pediatr Dermatol. 2004;21:670-674.
4. Meinking TL, Vicaria M, Eyerdam DH, et al. A randomized, investigator-blinded, time-ranging study of the comparative efficacy of 0.5% malathion gel versus Ovide Lotion (0.5% malathion) or Nix Crème Rinse (1% permethrin) used as labeled, for the treatment of head lice. Pediatr Dermatol. 2007;24:405-411.
5. Chosidow O, Giraudeau B, Cottrell J, et al. Oral ivermectin versus malathion lotion for difficult-to-treat head lice. N Engl J Med. 2010;362:896-905.
6. Ovide (malathion) lotion 0.5% package insert. Hawthorne, NY: Taro Pharmaceuticals, U.S.A., Inc; January 2007. 

Author’s Response
I appreciate Dr. Rutman’s and Ms. Shattuck’s clarifications regarding Ovide. I would stress that the degree of louse resistance to a pesticide such as malathion is not static, and I urge Taro to conduct more current studies in the U.S. for dissemination to the profession.
W. Steven Pray, PhD, DPh
Southwestern Oklahoma State University