Side effects are one of the major things a patient looks out for in a medication. The National Cancer Institute (NCI) defines an adverse effect as “an unexpected medical problem that happens during treatment with a drug or other therapy.” Unwanted effects can result from a physician’s advice and from medications or treatments, including complementary and alternative therapies. They can lead to complications.
Many Patients are frightened by potential side effects. They may have also experienced previous side effects with the same or similar medicine. Additionally, patients report not taking their medication because they may have witnessed side effects experienced by a friend or family member who was taking the same or similar medication. Seeing those side effects experienced by someone else may have led them to believe the medication caused those problems.
A wide range of medications has been reported to cause fatigue or tiredness which is one of the most common side effects of prescription and over-the-counter medicines. When medicines make you tired, it is often because they affect chemicals in your brain called neurotransmitters. Your nerves use them to carry messages to each other. Some of them control how awake or sleepy you feel. Some agents induce toxic myopathy that can lead to fatigue.
What is doxycycline?
Doxycycline is a broad-spectrum bacteriostatic agent synthetically derived from naturally occurring tetracyclines produced by Streptomyces sp. bacteria. Doxycycline was invented and clinically developed in the early 1960s by Pfizer Inc., New York, NY, and marketed under the brand name Vibramycin. Vibramycin received FDA approval in 1967, becoming Pfizer’s first once-a-day broad-spectrum antibiotic. The additional indication for malaria prophylaxis was obtained in 1994 with a supplemental New Drug Application. Doxycycline is on the World Health Organization’s List of Essential Medicines and is available as a generic medicine. In 2019, it was the 90th most commonly prescribed medication in the United States, with more than 8 million prescriptions.
Doxycycline is used to treat or prevent a variety of infections caused by bacteria, including:
• Pneumonia or other respiratory tract infections
• Infections of the skin or eye
• Infections of the lymphatic, intestinal, genital, or urinary systems
• Infections spread by ticks, lice, mites, and infected animals
• Infections spread by contaminated food and water
• Anthrax
• Plague or tularemia
• Malaria and MRSA
This medicine is also used to treat acne and rosacea (a skin condition that causes redness, flushing, and bumps on the face).
How should doxycycline be taken?
Doxycycline comes as a capsule, delayed-release capsule, tablet, delayed-release tablet, and suspension (liquid) to take by mouth. Doxycycline is usually taken once or twice a day. Drink a full glass of water with each dose. If your stomach becomes upset when you take doxycycline, you may take it with food or milk. However, taking doxycycline with milk or food may decrease the amount of medication absorbed from your stomach. Talk with your doctor or pharmacist about the best way to take doxycycline. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take doxycycline exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.
Swallow the delayed-release tablets and the Acticlate CAP capsules whole; do not split, chew, or crush them.
If you cannot swallow certain delayed-release tablets (Doryx; generics) whole, carefully break up the tablet and sprinkle the contents of the tablet on a spoonful of cold or room temperature (not hot) applesauce. Be careful not to crush or damage any of the pellets while you are breaking up the tablet. Eat the mixture right away and swallow without chewing. If the mixture cannot be eaten right away, it should be discarded.
Shake the suspension well before each use to mix the medication evenly.
If you are taking doxycycline for the prevention of malaria, start taking it 1 or 2 days before traveling to an area where there is malaria. Continue taking doxycycline each day you are in the area, and for 4 weeks after leaving the area. You should not take doxycycline for the prevention of malaria for more than 4 months. Continue to take doxycycline even if you feel well. Take all the medication until you are finished unless your doctor tells you otherwise.
One doxycycline product may not be able to be substituted for another. Be sure that you receive only the type of doxycycline that was prescribed by your doctor. Ask your pharmacist if you have any questions about the type of doxycycline you were given.
How quickly does doxycycline work?
Doxycycline is almost completely absorbed after oral administration. Peak concentrations are reached within two to three hours after dosing; however, it may take up to 48 hours before infection-related symptoms start to abate. How quickly you get better after doxycycline treatment is dependent on the severity of your condition. If you are using doxycycline for acne, you might start seeing improvement within 2 weeks, but it can take up to 12 weeks (or 3 months) to see the full benefit of the treatment. You’ll know doxycycline is working for you when you see less acne forming and your skin starts to look clearer. Even though you might feel better after a few days of treatment, it’s best to finish the entire antibiotic regimen in order to fully resolve your infection. This can also help prevent antibiotic resistance. Don’t stop your doxycycline regimen early unless your healthcare professional says you can do so.
Can doxycycline make you extremely tired?
Yes, extreme tiredness is listed as one of the rare side effects of taking doxycycline. While taking doxycycline, you may feel tired and fatigued. This may be a symptom of the infection being treated with the medication.
Doxycycline may also cause diarrhea, and in some cases, it can be severe. Doxycycline-induced diarrhea can make you so tired. The number one cause of fatigue after diarrhea is dehydration. During a bout of diarrhea, important fluids and electrolytes are flushed from your system which can lead to dehydration.
As dehydration progresses, the body redirects blood to the working muscles and away from the skin, impairing your body’s ability to diffuse heat. The increase in internal heat then results in muscle cramps, light-headedness, and fatigue. If you have chronic fatigue syndrome, you will identify with this symptom.
While antibiotics seem like straightforward medications, their side effects can be problematic, especially for the elderly. Some people have no trouble taking doxycycline, while others may feel even more rundown once they begin this medicine that is supposed to help them get better.
The important thing to remember is that just like every other medication you take, your doctor has weighed the risks and benefits of the drug and prescribed it for a reason. Even if you have the fleeting thought that you feel worse now than you did before you started doxycycline, you still should not stop taking it without consulting your doctor.
Side effects you may experience while taking doxycycline
Get emergency medical help if you have any signs of an allergic reaction to doxycycline: (hives, difficult breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning in your eyes, skin pain, red or purple skin rash that spreads and causes blistering and peeling).
Seek medical treatment if you have a serious drug reaction that can affect many parts of your body. Symptoms may include: skin rash, fever, swollen glands, flu-like symptoms, muscle aches, severe weakness, unusual bruising, or yellowing of your skin or eyes. This reaction may occur several weeks after you began using doxycycline.
Doxycycline may cause serious side effects. Call your doctor at once if you have:
• severe stomach pain, diarrhea that is watery or bloody;
• throat irritation, trouble swallowing;
• chest pain, irregular heart rhythm, feeling short of breath;
• little or no urination;
• low white blood cell counts – fever, chills, swollen glands, body aches, weakness, pale skin, easy bruising or bleeding;
• severe headaches, ringing in your ears, dizziness, nausea, vision problems, pain behind your eyes;
• loss of appetite, upper stomach pain (that may spread to your back), tiredness, nausea or vomiting, fast heart rate, dark urine, jaundice (yellowing of the skin or eyes).
Common side effects of doxycycline may include:
• nausea and vomiting;
• upset stomach;
• loss of appetite;
• mild diarrhea;
• skin rash or itching;
• darkened skin color;
• vaginal itching or discharge.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
