The Availability of Oral Medication for Head Lice
For most people, the go-to treatment for head lice is a topical solution applied directly to the hair and scalp. However, a prescription oral medication, ivermectin (brand name Stromectol), is available and can be used in certain circumstances. It is important to note that oral ivermectin is generally not considered a first-line treatment for head lice and is usually only prescribed by a healthcare provider after topical treatments have failed. Its use is also limited in children based on weight.
How Oral Ivermectin Works
Ivermectin is an antiparasitic drug that works by interfering with the nerve and muscle function of invertebrates like head lice. This mechanism is distinct from many topical treatments, which can be less effective against lice that have developed resistance. Oral ivermectin enters the bloodstream and kills the lice when they feed on the host's blood. The specific administration schedule is determined by a healthcare provider and may involve repeating the dose if necessary. This systemic action can be an advantage when dealing with widespread or persistent infestations.
The Standard of Care: Topical Treatments
Before considering an oral medication, most people should start with topical treatments, which are widely available and effective for many cases. These options include both over-the-counter (OTC) and prescription products.
Over-the-Counter (OTC) Topical Treatments
Most OTC lice treatments are applied as a wash, shampoo, or lotion. The two most common active ingredients are:
- Pyrethrins with piperonyl butoxide: Derived from the chrysanthemum flower, pyrethrins kill live lice but not unhatched eggs (nits). A second treatment is necessary 9–10 days after the first to kill any newly hatched lice before they can reproduce. Some resistance to pyrethrins has been reported.
- Permethrin lotion (1%): A synthetic pyrethroid, permethrin is similar to pyrethrins and kills live lice but not always the eggs. Like pyrethrins, it often requires a second treatment around day nine. Permethrin resistance is also known to exist in some lice populations.
Prescription Topical Treatments
If OTC products are unsuccessful, a doctor may prescribe a different topical medication, such as:
- Spinosad (Natroba): This suspension kills both live lice and eggs, often eliminating the need for a second application. Nit combing is not required for efficacy.
- Ivermectin lotion (Sklice): This topical form of ivermectin is FDA-approved for use in individuals aged six months and older and kills lice and newly hatched nymphs. It is also highly effective with a single application, eliminating the need for nit combing.
- Malathion (Ovide): This lotion is both pediculicidal and partially ovicidal. It is flammable and requires careful application, typically repeated after seven to nine days if live lice are still present.
The Indispensable Role of Nit-Combing
Regardless of the medication used, the physical removal of lice and nits (eggs) with a fine-toothed comb is a critical part of the treatment process. This technique, especially effective on wet hair with conditioner, ensures that any eggs that survived treatment are removed, preventing re-infestation.
Steps for Effective Nit-Combing:
- Prepare: Ensure the hair is wet and apply a generous amount of conditioner to help detangle and stun the lice.
- Section: Divide the hair into manageable sections and clip the un-combed parts away.
- Comb: Starting at the scalp, use a fine-toothed comb to systematically work through each section, wiping the comb on a paper towel after each pass.
- Rinse: After combing each section, rinse the hair to wash away any debris.
- Repeat: Repeat the combing process every few days for at least two weeks to ensure all newly hatched nymphs are removed before they can mature.
Comparison of Head Lice Treatment Methods
| Feature | Oral Ivermectin (Stromectol) | OTC Topical (Permethrin, Pyrethrin) | Prescription Topical (Spinosad, Ivermectin) |
|---|---|---|---|
| Application Method | Pill taken by mouth | Applied as a lotion, shampoo, or cream to the hair and scalp | Applied as a lotion or suspension to the hair and scalp |
| Effectiveness against Eggs | Kills hatching nymphs but not ovicidal; retreatment may be needed | Often requires retreatment as it may not kill all eggs | Kills both lice and eggs (spinosad) or hatching nymphs (ivermectin), reducing need for retreatment |
| Primary Use | Second-line treatment for resistant or failed cases | First-line treatment for most infestations | Alternative when OTC fails, or for specific patient needs |
| Nit-Combing | Not required for the medication to be effective, but recommended for cosmetic removal of dead nits | Strongly recommended to remove any surviving eggs and prevent recurrence | Not required for spinosad or topical ivermectin to work, but beneficial for cosmetic removal |
| Pros | Effective against resistant lice; single administration possible | Widely available; generally low cost | Highly effective; less chance of resistance |
| Cons | Prescription required; limited use in young children based on weight; not first-line | Growing resistance in some areas; requires careful timing of retreatment | Prescription required; higher cost than OTC options |
Environmental Cleaning and Prevention
While medication targets the lice on the head, taking steps to clean the environment is a good practice, though less critical than once believed. Head lice cannot survive for long without a human host.
- Wash bedding, clothing, and other washable items used by the infested person in hot water (at least 130°F / 54.4°C) and dry on high heat.
- Soak brushes, combs, and hair accessories in hot water for 5-10 minutes.
- Vacuum floors and furniture where the infested person spent time.
- Seal items that cannot be washed in a plastic bag for two weeks.
- Focus on head-to-head contact, as this is the most common mode of transmission, especially among children.
Conclusion
In answer to the question, Is there a pill for head lice? — yes, oral ivermectin (Stromectol) is a prescribed option, though it is not the primary course of action. For most cases, topical treatments remain the standard, effective approach. Success with any treatment method hinges on proper application, careful timing of retreatment if needed, and most importantly, diligent nit-combing. If initial topical treatments fail, consulting a healthcare provider to discuss alternative options like oral ivermectin or prescription topicals is the best next step. Always follow instructions and seek professional medical advice to ensure effective and safe treatment.
For more information on head lice, consult the Centers for Disease Control and Prevention guidelines [https://www.cdc.gov/lice/index.html].
