It is important that your doctor check your progress at regular visits to make sure that this medicine is working properly.
Do not take other medicines unless they have been discussed with your doctor. This especially includes over-the-counter (nonprescription) medicines for appetite control, asthma, colds, cough, hay fever, or sinus problems, since they may tend to increase your blood pressure.
This medicine may cause a loss of potassium from your body:
- To help prevent this, your doctor may want you to:
- eat or drink foods that have a high potassium content (for example, orange or other citrus fruit juices), or
- take a potassium supplement, or
- take another medicine to help prevent the loss of the potassium in the first place.
- It is very important to follow these directions. Also, it is important not to change your diet on your own. This is more important if you are already on a special diet (as for diabetes), or if you are taking a potassium supplement or a medicine to reduce potassium loss. Extra potassium may not be necessary and, in some cases, too much potassium could be harmful.
Check with your doctor if you become sick and have severe or continuing vomiting or diarrhea. These problems may cause you to lose additional water and potassium.
Before having any kind of surgery (including dental surgery) or emergency treatment, tell the medical doctor or dentist in charge that you are taking this medicine.
If you have a fever and there seems to be no reason for it, check with your doctor. This is especially important during the first few weeks you take this medicine since fever may be a sign of a serious reaction to methyldopa.
This medicine may cause some people to become drowsy or less alert than they are normally. This is more likely to happen when you begin to take it or when you increase the amount of medicine you are taking. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are not alert.
Dizziness, light-headedness, or fainting may occur, especially when you get up from a lying or sitting position. Getting up slowly may help, but if the problem continues or gets worse, check with your doctor.
The dizziness, light-headedness, or fainting is also more likely to occur if you drink alcohol, stand for long periods of time, exercise, or if the weather is hot. Drinking alcoholic beverages may also make the drowsiness worse. While you are taking this medicine, be careful in the amount of alcohol you drink. Also, use extra care during exercise or hot weather or if you must stand for long periods of time.
For diabetic patients:
- This medicine may raise blood sugar levels. While you are using this medicine, be especially careful in testing for sugar in your urine. If you have any questions about this, check with your doctor.
This medicine may cause dryness of the mouth. For temporary relief, use sugarless candy or gum, melt bits of ice in your mouth, or use a saliva substitute. However, if your mouth continues to feel dry for more than 2 weeks, check with your medical doctor or dentist. Continuing dryness of the mouth may increase the chance of dental disease, including tooth decay, gum disease, and fungus infections.
Hydrochlorothiazide may cause your skin to be more sensitive to sunlight than it is normally. Exposure to sunlight, even for brief periods of time, may cause a skin rash, itching, redness or other discoloration of the skin, or a severe sunburn. When you begin taking this medicine:
- Stay out of direct sunlight, especially between the hours of 10:00 a.m. and 3:00 p.m., if possible.
- Wear protective clothing, including a hat. Also, wear sunglasses.
- Apply a sun block product that has a skin protection factor (SPF) of at least 15. Some patients may require a product with a higher SPF number, especially if they have a fair complexion. If you have any questions about this, check with your health care professional.
- Apply a sun block lipstick that has an SPF of at least 15 to protect your lips.
- Do not use a sunlamp or tanning bed or booth.
If you have a severe reaction from the sun, check with your doctor
Before you have any medical tests, tell the doctor in charge that you are taking this medicine. The results of some tests may be affected by this medicine.