How Effective is Doxycycline For a Tick Bite?
Doxycycline is an effective antibiotic used to treat tick bites that cause illnesses. Doxycycline is an antibiotic, specifically a tetracycline derivative and is available as hyclate, monohydrate and calcium salts.
Tick bites can cause diseases and infections such as Lyme disease, Rocky Mountain spotted fever, Colorado tick fever, and cellulitis (skin infection) by transmitting microscopic parasites that infect red blood cells. According to the Centers for Disease Control and Prevention (CDC), approximately 30,000 people are diagnosed with Lyme disease each year and 6,000 a year from Rocky Mountain spotted fever.
Doxycycline is a standard treatment against illnesses caused by tick bites. Find out more about doxycycline and tick bites below.

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How Long Should You Take Doxycycline For a Tick Bite?
The length of time you should take doxycycline depends on the illness caused by tick bites. Doxycycline for tick bite dosages vary for each illness.
Clinician recommendations for Lyme disease are generally 100 mg twice daily for 10 to 28 days.
To treat mild to moderate cellulitis from a tick bite, doxycycline can be given 100 mg twice daily for 5 to 14 days.
To treat Rocky Mountain spotted fever as a result of a tick bite, the treatment is doxycycline 100 mg twice daily for 5 to 7 days or for at least 3 days after fever subsides.
If you were bitten by a tick but have no symptoms, a single dose of Doxycycline (200 mg) can also be used for prevention of Lyme disease if you meet criteria. These include: tick attachment for at least 36 hours, and tick bite in an area known to harbor Lyme disease, among others.
Some experts prefer a 10-day course of treatment for all tick bite illnesses.
How Quickly Will Doxycycline Work?
Once taken orally, doxycycline peaks within 1.5 to 4 hours with immediate release and 2.8 to 3 hours with extended-release capsules. Treatment guidelines suggest that doxycycline works better if you take it on an empty stomach, therefore it is suggested that doxycycline be administered on an empty stomach 1-2 hours before meals.
How Soon Do You Need Antibiotics After a Tick Bite?
If you have a known tick bite without symptoms, preventative doxycycline can be considered within 72 hours of tick removal. Otherwise, you can simply watch and wait, as oftentimes antibiotic treatment is not necessary. Your doctor can decide if doxycycline treatment is necessary for your tick bite.
Signs of illness after a tick bite include:
Fatigue
Lack of appetite
Headache
Myalgias
Arthralgias
Fever
Nausea
Vomiting
Abdominal pain
Rash - particularly if in the shape of a “bulls eye”
Altered mental status
Infection at tick site
Does Doxycycline Kill Ticks?
Doxycycline does not kill ticks but treats illnesses caused by tick bites. Doxycycline is an antibiotic that kills a wide variety of bacteria and parasites but does not kill ticks directly.
Chemicals that kill ticks directly are not safe for human consumption. Pesticides and insecticides can kill ticks instantly but are not safe to put on skin or handle without gloves. Usually, these chemicals are sprinkled along the yard to kill ticks and other insects.
What is the Best Time of Day to Take Doxycycline?
The best time of day to take doxycycline is 1 to 2 hours before meals. Some doxycycline prescriptions are prescribed twice a day, once in the morning and once in the evening. It is best to take these 1 to 2 hours before meals. For example, if you eat breakfast at 9:00 am, then it is best to take the dose between 7 and 8 am. If you usually eat dinner at 7:00 pm, then you should take the dose between 5 and 6 pm.
Taking doxycycline with a meal can decrease its effectiveness and decrease serum levels in the body. This means that if taken with a high-fat meal or milk, it may not work as intended and fight bacteria unsuccessfully. In addition, if you take oral contraceptives for birth control, doxycycline may cause your birth control to be less effective, so a back-up method is recommended while taking doxycycline.
Administration with iron or calcium may also decrease absorption of doxycycline. Food with high iron and calcium include:
Red meat
Seafood
Beans
Spinach
Iron-fortified cereals, breads, and pastas
Milk
Cheese
Other dairy products
Doxycycline Side Effects
Side effects of Doxycycline vary in intensity and incidence among patients. Side effects are generally not serious, and your doctor can help decide if the side effect may be bothersome enough to consider stopping medication, as is the case with any prescription medication.
Common side effects of doxycycline include:
Loss of appetite
Nausea
Vomiting
Diarrhea
Skin sensitivity to light
Adverse reactions are dangerous side effects that should be reported to your doctor immediately. Adverse reactions when taking doxycycline include:
Skin rash (hives, itching, redness, blistered, or peeling)
Swollen glands
Difficulty breathing or swallowing
Chest pain
Unusual bruising
Watery or bloody stool
Fever
Tightness in chest or throat
Swelling of face, lips, or tongue
Doxycycline Precautions
Doxycycline does cross the placenta; however, therapeutic doses of doxycycline during pregnancy are unlikely to produce substantial teratogenic risk. Doxycycline has been observed to accumulate in developing teeth and may cause permanent discoloration of teeth (yellow, gray, brown).
Doxycycline is found in breast milk and is considered safe to take while breastfeeding to treat Rocky Mountain spotted fever; however, doxycycline is not recommended if being used for maternal treatment of acne.
Doxycycline Interactions
Doxycycline interacts with certain foods, as stated above, as well as medications. The concentration of doxycycline in your blood may be less if taken with high fat food, large meals, or foods with iron and calcium. Taking doxycycline with alcohol may reduce the effectiveness and should be avoided.
Over 180 medications are known to interact with doxycycline. Commonly prescribed medications and OTC medications that interact with doxycycline include:
Anticoagulant drugs
Penicillin
Antacids and iron preparations
Oral contraceptives
Barbiturates and anti-epileptics
Penthrane
Doxycycline can also alter results of certain lab tests. Because of doxycycline’s interactions,, it is important to let your doctor know which medications you take. Your doctor can decide if doxycycline is safe to take.
Can You Get a Doxycycline Prescription Online?
Doxycycline is available as a prescription medication online. If you have an illness related to a tick bite, doxycycline may be the right medication for you.
At PlushCare, a doctor can perform an evaluation, diagnosis, and prescribe medication if needed. At your appointment, you can discuss the risks and benefits of taking doxycycline with your doctor and decide if it is the right treatment plan for you.
Read More About Doxycycline for Tick Bites
Sources:
PlushCare is dedicated to providing you with accurate and trustworthy health information.
Centers for Disease Control and Prevention (CDC). How many people get Lyme disease? Accessed on February 7, 2021. https://www.cdc.gov/lyme/stats/humancases.html
Centers for Disease Control and Prevention (CDC). Tick Bite Prophylaxis. Accessed on February 7, 2021. https://www.cdc.gov/ticks/tickbornediseases/tick-bite-prophylaxis.html
International Lyme and Associated Diseases Education Foundation. How to Handle a Tick Bite. Accessed on February 27, 2021. https://iladef.org/education/how-to-handle-a-tick-bite/
U.S. Food and Drug Administration. Doryx. Accessed on February 26, 2021 at https://www.accessdata.fda.gov/drugsatfda