Diethyltoluamide, DEET is a topically applied insect repellant. It helps to prevent infections transmitted by insect bites or prevent infestations by insects or other arthropods. DEET is effective against biting flies (black flies, deer flies, gnats, sandflies, stable flies), fleas, chiggers, mosquitoes, and ticks. Products are available with DEET concentrations ranging for 5% to 100%. Higher concentration products have a longer duration of action but are not more effective than lower concentration products.
General Administration Information
For storage information, see the specific product information within the How Supplied section.
Route-Specific Administration
Topical Administration
-Avoid use near eyes and mucous membranes.
-Do not apply over cuts, wounds, irritated skin, sunburnt skin, or under clothing.
-Do not allow children to handle this product.
Other Topical Formulations
Spray Formulation
-Hold canister 4 to 12 inches away and apply to exposed skin and clothing using a slow sweeping motion.
-Avoid frequent reapplication and saturation.
-Do not spray directly onto the face. To apply to the face, spray palms of hand and apply sparingly.
-Do not spray in enclosed area; avoid inhalation of the spray.
-Do not apply to plastic, leather, acetate rayon, spandex, or colored fabrics other than nylon. Avoid spraying on nail polish, watch crystals, eyeglass frames, furniture, and painted or varnished surfaces.
Skin irritation, contact dermatitis, pruritus, and angioedema have been reported following topical application of diethyltoluamide, DEET.
Psychosis has been reported by 1 adult after topically applying 70% diethyltoluamide, DEET. Other serious adverse events associated with DEET have occurred following inappropriate ingestion or exposure to the eye. Cases of hypotension, seizures, coma, and deaths have occurred within 1 hour of ingesting DEET. Ocular exposure has resulted in substantial, but reversible, conjunctival damage.
Do not apply diethyltoluamide, DEET under clothing or over a skin abrasion (i.e., cuts, wounds, irritated or sunburnt skin). To avoid accidental exposure (i.e., ingestion, inhalation, ocular exposure) do not sprayed the product in an enclosed area or directly onto the face. If accidental ocular exposure occurs, slowly rinse the eye with water for 15 to 20 minutes. Contact lenses, if present, should be removed after the first 5 minutes of rinsing. If the product is swallowed, drink water and seek immediate medical attention or call the Poison Control Center. Do not induce vomiting unless told to do so by a health care provider.
Diethyltoluamide, DEET is not FDA approved for use on children younger than 2 years of age. Children have an increased surface-area-to-body-mass ratio and may be at increased risk for toxicity due to greater skin absorption; however, reports of DEET-related toxicity are rare and several publications suggest that DEET use in children is quite safe using available products. The American Academy of Pediatrics (AAP) and Centers for Disease Control and Prevention (CDC) recommend use of products with DEET concentrations between 10% and 30% for infants and children 2 months of age or older when there is a need to prevent insect-borne disease (e.g., Lyme Disease, Chikungunya virus, West Nile Virus). The effectiveness is similar for 10% and 30% DEET-containing products, but the duration of effect varies from 2 hours (for 5% DEET) to 6 hours (for 30% DEET). Since higher concentrations do not provide greater efficacy, use lower concentration products to provide the required duration of protection. To avoid accidental ingestion or ocular exposure, adults should apply the product to children. Avoid spraying directly onto the face of a child and never apply the product to children's hands. Keep DEET out of the reach of pediatric patients (i.e., neonates, infants, children).
The Centers for Disease Control and Prevention (CDC) considers diethyltoluamide, DEET to be safe for use during pregnancy, and encourages its use by pregnant women for protection against Zika virus infection and Lyme disease. Human data regarding use of DEET during pregnancy are limited. In one case report, daily DEET application by the mother was associated with fetal craniofacial malformations (hypertelorism, poorly developed philtrum, broad nasal bridge) and developmental delay. In addition, a case-control study found the odds ratio for hypospadia to be 1.81 (95% CI; 1.06, 3.11) following maternal exposure to unspecified insect repellents. However, a randomized control trial involving 897 pregnant women exposed to DEET during the 2nd and 3rd trimester found no evidence of fetal harm. DEET does appear to cross the placenta; however, physical and neurologic examinations of 4 newborns with detectable quantities of DEET in cord blood were normal at birth and throughout the first year of life.
The Centers for Disease Control and Prevention (CDC) considers diethyltoluamide, DEET to be safe for use during breast-feeding; however, data are limited regarding excretion of the drug in human breast milk. To prevent accidental ingestion by the infant, instruct mothers not to apply DEET topically to the breast while breast-feeding. Consider the benefits of breast-feeding, the risk of potential infant drug exposure, and the risk of an untreated or inadequately treated condition. If a breast-feeding infant experiences an adverse effect related to a maternally administered drug, health care providers are encouraged to report the adverse effect to the FDA.
The spray formulation of diethyltoluamide, DEET is flammable. Avoid use near a fire or flame, including tobacco smoking during or immediately after application.
For insect bite prophylaxis and insect infestation prophylaxis:
Topical dosage:
Adults: Apply topically to exposed skin and clothing using a slow sweeping motion. To apply to the face, spray palms of hand and apply sparingly; do not spray directly onto the face. Do not apply near the eyes or mouth. Use sparingly around ears. Do not apply to over cuts, wounds, irritated skin, sunburnt skin, or under clothing. Reapply as needed; however, frequent reapplication and saturation are unnecessary and should be avoided.
Children and Adolescents 2 years and older: Apply topically to exposed skin and clothing using a slow sweeping motion. Do not apply to children's hands or spray directly onto the face. When applying to the face, spray own hand and apply sparingly; avoid application near the eyes or mouth. Do not apply to over cuts, wounds, irritated skin, sunburnt skin, or under clothing. Reapply as needed; however, frequent reapplication and saturation are unnecessary and should be avoided.
Infants and Children 2 months through 1 year: The American Academy of Pediatrics (AAP) and Centers for Disease Control and Prevention (CDC) recommend use of products with DEET concentrations 30% or less for infants and children 2 months of age or older. Since higher concentrations do not provide greater efficacy, use lower concentration products to provide the required duration of protection, (i.e., 2 hours for DEET 5% and 6 hours for DEET 30%).
Maximum Dosage Limits:
-Adults
No maximum dosage information is available.
-Geriatric
No maximum dosage information is available.
-Adolescents
No maximum dosage information is available.
-Children
2 years and older: No maximum dosage information is available.
1 year: Safety and efficacy not established; AAP and CDC recommend use of products with up to 30% DEET.
-Infants
2 months and older: Safety and efficacy not established; AAP and CDC recommend use of products with up to 30% DEET.
1 month: Safety and efficacy not established.
Patients with Hepatic Impairment Dosing
Specific guidelines for dosage adjustments in hepatic impairment are not available; it appears that no dosage adjustments are needed.
Patients with Renal Impairment Dosing
Specific guidelines for dosage adjustments in renal impairment are not available; it appears that no dosage adjustments are needed.
*non-FDA-approved indication
There are no drug interactions associated with Diethyltoluamide, DEET products.
The mechanism of action of diethyltoluamide, DEET is unknown. It is theorized that DEET disrupts receptors in the antennae of mosquitos, thereby blocking their ability to locate humans. In addition to preventing mosquito bites, DEET also repels ticks, biting flies (black flies, deer flies, gnats, sandflies, stable flies), fleas, and chiggers. Products are available in concentrations ranging from 5% to 100% DEET. Although products with higher DEET concentrations have a longer duration of action, they are not more effective than lower DEET concentrations products. In addition, the duration of action appears to plateau at concentrations of 50%. Based on this data, Health Canada has phased out insect repellents with DEET concentrations greater than 30% which provides protection for approximately 6 hours.
Diethyltoluamide, DEET is applied topically to exposed skin. Once absorbed into systemic circulation, the drug is metabolized by hepatic enzymes, with only 10% to 14% of the absorbed dose being recovered unchanged in urine. The elimination half-live of DEET is 2.5 hours.
Affected cytochrome P450 isoenzymes and drug transporters: None
-Route-Specific Pharmacokinetics
Topical Route
Diethyltoluamide, DEET is absorbed through the skin, with systemic bioavailability ranging from 9% to 56% of the topically applied dose after 6 hours.
-Special Populations
Other
Pregnancy
Diethyltoluamide, DEET appears to cross the placenta. In one study, 50 cord blood samples were obtained from pregnant women exposed to DEET. No DEET was detected in 46 of the 50 samples. Of the remaining 4 samples, 1 contained 2.44 mcg/mL of DEET and the other 3 contained 1 mcg/mL. The mothers with detectable cord blood applied a total DEET dose of 190.4, 204, 246.5, and 249.9 grams of DEET during the 16, 17.1, 20.7, and 21 weeks, respectively.