A Pharmacist's Guide to OTC Therapy

JULY 01, 2008
Yvette C. Terrie, BSPharm, RPh

Ms. Terrie is a clinical pharmacy writer based in Haymarket, Virginia.

Head Lice Treatments

Inspection for Head Lice

• Examine each member of the household for lice or nits by using a magnifying glass and bright light

• Look for nits near the scalp starting at the beginning of the neck and behind the ears

• Look for small white-to-yellow specks the size of poppy seeds, and for adult lice moving quickly away from the light

• Examine only a small section of the hair at a time

• If evidence of lice/nits is present, consult a pharmacist or physician for possible treatment options

Adapted from references 3-5.

Pediculus humanus capitis, commonly referred to as head lice, affects an estimated 10 million to 12 million individuals in the United States annually and is most prevalent among children aged 3 to 12 years.1 Although head lice can occur at any time during the year, the peak times for outbreaks are typically between August and November.1 Head lice can be transmitted via direct contact with an infested individual or through indirect contact with a contaminated item, such as a hat, hairbrush, or towel.1,2

OTC pediculicides currently on the market for the treatment of head lice contain permethrins and synergized pyrethrins. Both of these products are contraindicated for use in individuals who have hypersensitivities or allergies related to chrysanthemums, ragweed, or pyrethrins.1

Pyrethrin products should be applied to the hair for 10 minutes and then rinsed with warm water or shampooed as directed, followed by combing through the hair with a lice comb to remove nits. This procedure should be repeated in 7 to 10 days to kill any remaining nits. Pyrethrin products are available in various formulations, such as shampoos, lotions, and mousses. In addition, many of these products typically contain a nit removal comb.

Removal of Head Lice/Nits

• Use disposable gloves when removing nits and work in a well-lit area

• Part hair into 4 sections starting at the top of the head. Hair should be damp If hair dries, rewet with water.

• Using a 1- to 2-in strand of hair, place comb close to scalp and comb firmly away from the scalp

• Pin back area that has been combed and proceed with other sections of the hair

• Clean comb often while combing by using a tissue to wipe away nits and discard the tissue in a sealed plastic bag

• Check hair daily for lice or nits

• Always clean comb after each use

Adapted from references 3-5.

After the hair has been shampooed with regular shampoo without conditioner, rinsed, and towel dried, permethrin cream rinses should be applied to the hair for 10 minutes and then rinsed with warm water. The hair should then be combed with a lice comb. The rinse has a residual effect for up to 10 days.1 A second application of permethrin cream rinses should only be used after 7 to 10 days if active lice are still detected.1 Products containing permethrin are available as 1% cream rinses.

Counseling Points

When used as directed, OTC products can be very effective in treating head lice. Patients/caregivers should be reminded to adhere to the directions given by the manufacturer of the selected product and inspect the infested area routinely for nits, using the appropriate combing technique for removal of nits. If all nits are not gone after the first treatment, a second application should be applied.

Lice Removal Combs

Nix Premium Metal Two-Sided Lice Comb

LiceGuard Robi Electronic Lice Comb

LiceMeister Comb

RID Dual Combing System

Adapted from references 3-5.

The scalp and hair should be thoroughly examined for at least 7 to 10 days. If head lice infestation persists after a second application, individuals should consult their health care provider immediately for other treatment options. As a result of concerns about an increase in lice resistance to pediculicides, it is important for pharmacists to remind patients about the overuse of these products, noting that resistance may be caused by improper use, excess use, or insufficient contact time.1,2 Patients also should be reminded to avoid unnecessary use of these products. Individuals with signs of a secondary dermatologic infection in the infested area and women who are pregnant or lactating should always be referred to their primary health care provider for treatment before using any of these products.1

Miscellaneous Products

Brand Name

Active Ingredient(s)

Hair Clean 123 Completely Natural Lice Kit

coconut oil, anise oil, ylang ylang oil, isopropyl alcohol

Lice Free Hair Gel

natrum muriaticum 1X (sodium chloride USP)

LiceGuard Lice Treatment System

purified water, sodium laureth sulfate, quaternium-80, polyquaternium-11, panthenol, allantoin, disodium EDTA, fragrances, glycol distearate, sodium laureth sulfate, cocamide MEA

RID Lice Control Spray (for nonwashable items)

permethrin 0.5%

RID Pure Alternative: Head Lice Remedy


Nix Lice Control Spray for the Home

permethrin 0.25%

Pharmacists can assist patients in the selection of the various OTC products currently on the market, as well as be instrumental in ensuring that these products are used properly by providing the patient with adequate counseling. When counseling patients about these products, pharmacists should relay the importance of nonpharmacologic measures to prevent transmission of head lice to another individual and prevent possible reinfestation. Examples of these measures include1,2:

  • Adequately clean personal items by washing brushes, combs, hats, and toys with very hot water (≥130° F) for at least 10 minutes
  • Ensure appropriate cleaning of the living environment by vacuuming carpets, rugs, mattresses, and upholstered furniture
  • All linens should be laundered in hot (130° F) soapy water. Dry these items on the hottest dryer setting, if possible.
  • Seal objects that cannot be laundered in plastic bags for at least 2 weeks
  • Refrain from sharing items such as combs, brushes, hats, helmets, and towels

For more information on head lice, please visit the National Pediculosis Association at www.headlice.org.

OTC Pediculicide Products

Brand Name

Active Ingredient(s)

A 200 Lice Treatment

Kit Shampoo: pyrethrum extract equivalent to 0.33% pyrethrins; piperonyl butoxide 4%
Lice Spray: permethrin 0.50%

Nix Crème Rinse

Permethrin 1%

Nix Combing Gel and Metal Comb

Permethrin 1%

Nix Complete Lice Removal Kit

Permethrin 1%

Pronto Lice Killing Shampoo 0.33%

Piperonxyl butoxide 3%; pyrethins

Pronto Plus Maximum Strength Lice Killing Mousse Shampoo Kit Plus Vitamin E

Pyrethrum extract pyrethrins 0.33%; Piperonyl butoxide 4%

Pronto Plus Lice Killing Warm Oil Treatment & Conditioner

Pyrethrum extract pyrethrins 0.33% piperonyl butoxide 4%

Pronto Plus Complete Lice Removal System (contains lice killing shampoo and lice egg remover plus antiseptic)

Shampoo: pyrethrum extract pyrethrins 0.33%; piperonyl butoxide 4%
Lice Egg Remover Plus Antiseptic: benzalkonium chloride 0.1%

Pronto Plus Maximum Strength Lice Killing Hair & Scalp Masque Apple with Herbal Scent

Pyrethrum extract pyrethrins 0.33%— piperonyl butoxide 4%

RID Lice Shampoo Piperonxyl

butoxide 3%; pyrethins 0.33%

RID Unique Three Step Lice Elimination System Complete Kit

Shampoo: piperonyl butoxide 4%; pyrethrins 0.33%
Comb-Out Gel: water, glycerin, hydroxyethylcellulose, behenamidopropyl dimethylamine behenate, cabbage extract
Home Control Spray: permethrin 0.50% (3-phenoxphenyl) methyl cix/trans3-(2-2 dichloroethenyl) 2,2 dimethylcyclopropanecarboxylate


  1. Buff W, Fuhrman C. Insect Bites and Stings and Pediculosis. In: Berardi R, Kroon L, Newton G, et al, eds. Handbook of Nonprescription Drugs. 15th Edition. Washington, DC: American Pharmacists Association; 2006:794-800.
  2. National Pediculosis Association Web site. www.headlice.org.
  3. Rid Lice Products. Bayer Health Web site. www.ridlice.com/healthcare.html.
  4. Nix Lice Treatment. Insight Pharmaceuticals Web site. www.nixlice.com
  5. Pronto Plus Products. Del Pharmaceuticals Web site. www.prontoplus.com/index.cfm.

Herbal Supplements

The use of herbal supplements has increased in the last 10 to 15 years, and an estimated 25% of adults use one or more herbal supplements to treat a medical condition.1 Herbal supplements are defined as dietary supplements derived from a plant source, including the leaves, stems, flowers, roots, and seeds.1 Herbal supplements are available as single-entity or combination products. In addition, some multivitamin/mineral supplements are now formulated with herbal supplements, such as ginkgo biloba and ginseng.

According to an article by Bent and Ko, published in the April 2004 issue of the American Journal of Medicine, of the 10 most frequently used herbal supplements in the United States in 2001, only 4 herbs—garlic, ginkgo biloba, saw palmetto, and St. John's wort—have systematic reviews that report statistically significant evidence of efficacy.1

Many patients may assume that herbal supplements are generally safe because they are derived from natural sources; however, many patients with preexisting medical conditions and/or those patients concurrently taking other medications—including prescription and OTC agents—may not be awaretematic reviews that report statistically significant evidence of effi of the potential for drug–herbal supplement interactions.

Examples of Possible Herbal Supplement–Drug Interactions

• Supplements such as garlic, ginkgo, ginseng, St. John's wort, and evening primrose oil may increase the international normalized ratio in individuals taking warfarin, thus increasing the incidence of bleeding
• Ginkgo may reduce the effectiveness of anticonvulsants
• Ginseng may intensify the effects of antihypergylcemic drugs, thus increasing incidence of hypoglycemia
• St. John's wort can cause a decrease in the plasma concentrations of agents such as amitriptyline cyclosporine, digoxin, and theophylline. In addition, St. John's wort also may cause breakthrough bleeding and decrease the effectiveness of oral contraceptives
• Valerian may produce an increased sedative effect when used with alcohol and other central nervous system depressants
• Kava may reduce the efficacy of levodopa and is contraindicated for use with other agents and herbs that may cause hepatic damage
• Garlic supplements may intensify the effects of some antihypertensive agents

Adapted from references 1, 2, 5, and 6.

Sood et al reported that the potential for significant drug–herbal supplement interactions appears to be most common in the following drug classes: antithrombotic medications, sedatives, antidepressant agents, and antidiabetic agents. These accounted for an estimated 94% of the potential clinically significant interactions.2 The drug most commonly documented for a potential drug–herbal supplement interaction is warfarin.2 Furthermore, Sood et al reported that the 5 most common herbal supplements associated with potential drug interactions are garlic, valerian, kava, ginkgo, and St. John's wort.2

Results from a national survey reveal that an estimated 18.4% of patients using prescription medications also used herbal remedies.2 In addition, many patients do not report the use of these herbal supplements, making it more difficult to screen for possible drug–supplement interactions or contraindications. Results from another survey reported that an estimated 63% of participants did not inform their primary health care provider about their use of dietary supplements.3 Sood et al concluded that, although the potential for interactions between prescription drugs and herbal supplements appears to be high, the actual potential for harm is relatively low.2

Pharmacists can be a fundamental source of information for patients seeking guidance about the safety and efficacy of herbal supplements. When counseling patients about prescription and OTC medications, pharmacists should ascertain if the patient is currently using herbal supplements in order to assess for possible drug interactions or contraindications. Likewise, when assisting patients in the selection of herbal supplements, pharmacists should screen for possible drug interactions and contraindications.

Factors to be considered when evaluating the clinical significance of an herbal supplement–drug interaction include the particular herb, the drug, and the medical history of the patient.4 Patients should be reminded to discuss the use of herbal supplements with their primary health care provider prior to using them and to always include these supplements as part of their medication profile. Women who are pregnant or lactating should never use an herbal supplement without consulting their primary health care provider.

In addition, it is important to remind patients to always use herbal supplements from reputable manufacturers and to adhere to the patient instructions provided. Patients also should be reminded that if they experience any adverse effects to report them to their primary health care provider immediately.

For more information regarding herbal supplements, please visit the National Institutes of Health's National Center for Complementary and Alternative Medicine at nccam.nih.gov.

Most Commonly Used Herbal Supplements

Herbal Supplement

Examples of Common Uses

Potential Adverse Effects


Immune stimulant to prevent and treat colds and other upper respiratory infections

Fatigue, dizziness, headache, and GI symptoms


Hypercholesterolemia, hypertension, peripheral arterial disease

Nausea; burning sensation in mouth; throat, and stomach; halitosis; and body odor

Ginko biloba

Cognitive impairment, vascular dementia, tinnitus

Nausea, dyspepsia, headache, and heart palpitations

Saw palmetto


Headache and diarrhea


Mental and physical stress, anemia, diabetes, and insomnia

Anorexia, rash, changes in blood pressure, and headache

Grape seed extract

Chronic venous insufficiency, diabetic retinopathy, and atherosclerosis

No adverse effects reported in literature

Green tea

Protections against cancer, cardiovascular disease, and hepatic disorders

Insomnia, anxiety, and tachycardia

St. John's wort

Depression, pain, anxiety, and insomnia

Photosensitivity, xerostomia, dizziness, and confusion


Vision impairment

No adverse effects reported in literature


Aloe Topical aloe: promotion of wound healing and dermatitis
Oral aloe: digestive disorders wash stimulation

Allergic reactions and urticaria. The use of topical aloe is contraindicated in individuals with allergy to plants in the Liliaceae family.

GI = gastrointestinal; BPH = benign prostatic hypertrophy.
Adapted from references 1, 5, and 6.


  1. Bent S, Ko R. Commonly used herbal medicines in the United States: a review. Am J Med. 2004;116(7):478-485.
  2. Sood A, Sood R, Brinker FJ, Mann R, Loehrer LL, Wahner-Roedler DL. Potential for interactions between dietary supplements and prescription medications. Am J Med. 2008;121(3):207-211.
  3. McQueen C, Hume A. Introduction to Botanical and Nonbotanical Medicines. In: Berardi R, Kroon L, Newton G, et al, eds. Handbook of Nonprescription Drugs.15th Edition. Washington, DC: American Pharmacists Association; 2006:1095.
  4. Hu Z, Yang X, Ho PC, et al. Herb-drug interactions: a literature review. Drugs. 2005;65(9):1239-1282.
  5. Hume, Anne and Strong, Kathryn. Botanical Medicines. In: Berardi R, Kroon L, Newton G, et al, eds. Handbook of Nonprescription Drugs.15th Edition. Washington, DC: American Pharmacists Association; 2006:1104-1136.
  6. Dermatological Disorders. In: Beers M, ed: The Merck Manual of Diagnosis and Therapy.18th Edition. Rahway, NJ: Merck Publishing; 2006:2724-2728.

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