The usual dose is 100mg to 200mg once or twice a day. If you’re taking doxycycline more than once a day, try to space your doses evenly throughout the day. If you take it twice a day, this could be first thing in the morning, and in the evening.
If you’re experiencing symptoms of pharyngitis, your doctor will look at your throat. They’ll check for any white or gray patches, swelling, and redness. Your doctor may also look in your ears and nose. To check for swollen lymph nodes, they will feel the sides of your neck.
Within 24 h following exposure to relatively intense sunshine, the typical initial skin symptom of a phototoxic reaction to doxycycline is a sunburn-like sensation (burning, erythema) in sun-exposed areas like the nose, upper cheeks, lips, and dorsal aspects of the forearms, hands, and fingers, partially resembling Mar 15, 2017
Some products that may interact with this drug include: retinoid medications taken by mouth (such as acitretin, isotretinoin), barbiturates (such as phenobarbital), “blood thinners” (such as warfarin), digoxin, anti-seizure medications (such as phenytoin), strontium.
 six of 15 patients receiving doxycycline 200 mg initially and 100 mg twice daily for 7 days developed abnormal sunburn and 10 of 15 patients had paresthesias consisting primarily of tingling sensations and burning of exposed body areas including the hands, feet, and nose.