1 What is Kwell?

Brand: Kwell, Thionex

Generic: Lindane

Kwell is used to treat head and pubic lice, and scabies that have failed from other treatments. Lindane is an insecticide that kills parasites such as human lice and mites that cause scabies, as well as their eggs. Doctors prescribe Lindane shampoo to treat head lice and pubic lice, while Lindane lotion is used to treat scabies.

Lindane is only used for lice and mites infestations that did not respond to previous treatments, or for patients who cannot tolerate side effects of previous treatments.

Lindane is a prescription medication. Lindane is a poison and can cause poisoning if used improperly.

Lindane is a hazardous substance and may affect the liver, kidneys, and central nervous system. Lindane is used only if other safer treatments failed to respond or has caused severe side effects. Lindane may cause seizures and death, especially if used for extended periods or if used on children. Applying Lindane on broken skin may allow significant amounts of it to enter the body, which increases the risk of side effects.

Using Lindane improperly can cause serious side effects or death. Only use Lindane as instructed by the doctor.

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2 What to know before using

Your doctor will inform you of what you need to know before using Kwell.

Do not use Lindane if you experienced allergies to Lindane shampoos or lotions.

You cannot use Lindane if you have the following conditions:

  • History of seizures or have disease that causes seizures, such as epilepsy
  • Allergic to any ingredient used in Lindane shampoos or lotions
  • If you are breast-feeding
  • Recently used Lindane before
  • Having broken or irritated skin conditions such as dermatitis and psoriasis
  • Have crusted (Norwegian) scabies

Note that only adults and children weighing at least 49.9 kilos (110 pounds) can use Lindane shampoos and lotions.

Lindane preparations cannot be used on very young infants and premature babies, which have more permeable skin that allow Lindane to enter the body.

If you are pregnant or breastfeeding, tell it to your doctor before using Lindane. Lindane is not proven to be completely safe for the unborn baby when given to pregnant patients. Do not nurse a baby when receiving Lindane because it may be expressed in breast milk and cause adverse effects.

Tell the doctor all your health conditions before using Lindane.

The doctor need to know if you have the following health problems before prescribing Lindane:

  • Heart disease
  • History of head injury, or brain or spinal cord tumors
  • Having HIV or AIDS
  • Liver diseases such as cirrhosis
  • If you are an alcoholic

Note that oils can enhance the absorption of Lindane in the skin, which can lead to side effects. Make sure not to apply any lotions, creams or ointments to the skin before applying Lindane shampoo or lotion.

Tell the doctor all the medicines you take before receiving Lindane, which is useful in avoiding undesirable drug interactions.

The doctor needs to know if you take the following medications:

  • Antipsychotic drugs such as Amitryptiline
  • Antidepressants
  • Theophylline
  • Cyclosporine, Mycophenolate Mofetil, Tacrolimus capsules
  • Penicillins, Imipenem, Quinolone antibiotics
  • Chloroquine sulfate, Pyrimethamine
  • Isoniazid
  • Meperidine
  • Radiographic contrast agents
  • Centrally active anticholinesterases
  • Sedatives such as Phenobarbital and Diazepam
  • Methocarbamol

Note that lice infestation and scabies are highly contagious. When a patient is prescribed with Lindane, the patient’s close family members, and sexual partners must also be notified and treated as well. If only the patient receives treatment, he or she is very likely to become infected again from others.

3 Proper usage

To use Kwell properly, you must follow all instructions given by your doctor.

Lindane lotion and shampoo preparations are applied on the skin. Both preparations are for external use only and must never be applied to the broken or irritated skin. Lindane lotion and shampoo are usually used only once.

Lindane lotion and shampoo have specific instructions in using to ensure that the drug does not enter the body. Always follow your doctor’s prescription in using Lindane preparations. Read and understand the information guide found in the packaging of Lindane preparations. Ask your doctor or pharmacist if you have questions.

Lindane shampoos are only used for head and pubic lice infestation, and must be used as directed by the doctor.

Here are the steps to use Lindane shampoos properly:

  • Wash hair first with regular shampoo (do not use hair conditioner). Wait at least one hour after shampooing before using Lindane. Make sure your hair is completely dry before using Lindane shampoo. This will lessen the chance of absorbing Lindane through the skin.
  • Shake Lindane shampoo bottle well before using it.
  • Wear disposable nitrile, latex with neoprene or sheer vinyl gloves first. Apply a light coat of Lindane shampoo on the dry hair and scalp. It is not important to make it lather this time. Do not use or add water.
  • Work the shampoo well and make sure to pay extra attention to fine hairs on the neck and behind the ears. Leave exactly for 4 minutes. Use a timer.
  • To wash it off, add a little warm water. After it lathers, rinse immediately with water. When rinsing, take extra caution not to apply the lather on other skin surfaces, the eyes, nose or mouth. You can remove gloves at this time.
  • Dry your hair with a towel. Wash hands thoroughly.
  • Remove nits or dead lice with specialized nit comb or tweezers.
  • Wash combs, hair brushes, hats, recently worn clothing and bed linens in very hot water, or dry clean them, to kill any lice or their eggs.
  • Make sure to do repeated combing to detect live or dead lice, and report them to the doctor.
  • Lindane lotion is used to treat scabies. Lindane lotion has specific instructions for use to become effective in killing mites and treating scabies:
  • Lindane lotion must be applied to clean dry skin. You can shower or bathe at least one hour before applying Lindane lotion. Do not apply any oil, lotion or cream on the skin. Make sure the skin is completely dry before applying Lindane.
  • Shake Lindane lotion bottle well.
  • Caregivers applying Lindane should wear gloves made from nitrile, clear vinyl or latex with neoprene. Lindane may penetrate latex gloves so do not use it.
  • Apply a very thin layer of Lindane lotion on the skin, from the neck downwards. Make sure to pay attention to folds of skin, which scabies mites tend to reside. Also, apply Lindane lotion under the fingernails using a toothbrush (trim your fingernails short).
  • Do not put any plastic or impervious covering on the skin where Lindane lotion is applied.
  • You can wash Lindane lotion completely after 8 to 12 hours. Do not leave Lindane lotion on skin for more than 12 hours. Only use warm water in washing. Hot water may allow Lindane to become absorbed in the skin.
  • Make sure to dry clean recently worn clothing, underwear, night wear, sheets, pillowcases, and towels, or wash them all in very hot water, to kill scabies mites.
  • Lindane lotion may cause skin itching, which may be mistaken for scabies. Skin itching may occur for few weeks. Call your doctor if you still experience itching 4 weeks after application of Lindane lotion.

You have to use Lindane lotion or shampoo only once. If you missed a dose of Lindane lotion or shampoo, use them as soon as you remember.

Dispose of Lindane lotion or shampoo bottle immediately after use, even if there is still some medicine left. Wrap used items like towels and toothbrushes (used in applying Lindane under fingernails) in paper or plastic for disposal. Keep them away from the reach of children or animals. Do not store or use leftover Lindane preparations.

Poisoning can occur if you used too much Lindane lotion or shampoo, or if they are swallowed. If these things happened, call local poison control hotlines for immediate medical assistance.


Lindane lotion and shampoos at room temperature, away from moisture and heat.

4 Precautions to take

Before using Kwell, there are some precautions you must take.

When applying or washing off Lindane lotion or shampoo, take care not to get the medicine on eyes, nose, ears or mouth. If this happens, wash the area with running water for at least 5 minutes.

Lindane is poisonous and must be used only as directed by the doctor. Lindane is supplied in single-used bottles, which is usually enough for one application only.

Do not let anyone touch the skin area where Lindane lotion or shampoo was applied. Keep your distance from children or pregnant individuals for a while after using Lindane.

Lice infestations and scabies are very contagious. Do not engage in sex or intimate contact with anyone until the doctor tells you it is safe to do so.

If scabies or lice infestation occurred a few weeks later after using Lindane, call your doctor first. You cannot use Lindane if you just recently used it.

Make sure not to apply any oil, cream, ointment, lotion on the skin, or bathe in hot water, before applying Lindane. Oil and hot water may allow skin to absorb Lindane.

It is very important not to apply Lindane on broken or irritated skin.

If you are receiving Lindane, do not take any medicine or herbal substances without asking your doctor.

If you became pregnant or did breastfeeding while using Lindane, call the doctor right away.

5 Potential side effects

As with many medications, there are several potential side effects associated with Kwell.

Call your doctor immediately if you experienced the following symptoms:

  • Severe allergic reaction symptoms such as hives, difficulty breathing, swelling of the face, lips, mouth or throat.
  • Convulsions or seizures
  • Problems with vision, speech or balance
  • Severe dizziness