Hydrochlorothiazide 50mg Tablets
Overview
What is this medicine?
How to Use This Medicine
To get the most benefit from your medication, follow your doctor's instructions carefully. Read all the information provided with your prescription and follow the instructions closely.
Continuing Your Medication
Continue taking your medication as directed by your doctor or healthcare provider, even if you start to feel better. It's essential to take your medication as prescribed to ensure its effectiveness.
Managing Potential Side Effects
This medication may increase the frequency of urination. To minimize sleep disturbances, try to avoid taking your medication too close to bedtime.
Oral Suspension Instructions
You can take the oral suspension with or without food. Before each use, shake the suspension well to ensure the medication is evenly mixed. Measure the liquid dose carefully using the measuring device provided with the medication. If a measuring device is not included, ask your pharmacist for one to ensure accurate dosing.
Storing and Disposing of Your Medication
To maintain the quality and effectiveness of your medication:
Store it at room temperature, away from direct light.
Keep it in a dry place, avoiding storage in a bathroom.
* Ensure the lid is tightly closed when not in use.
Missing a Dose
If you miss a dose, take it as soon as you remember. However, if it's close to the time for your next scheduled dose, skip the missed dose and resume your regular dosing schedule. Do not take two doses at the same time or take extra doses to make up for a missed one.
Lifestyle & Tips
- Take this medication exactly as prescribed, usually once daily in the morning to avoid nighttime urination.
- Do not stop taking this medication without consulting your doctor, even if you feel well.
- Maintain a balanced diet, and discuss potassium intake with your doctor, as this medication can lower potassium levels.
- Limit alcohol intake, as it can increase the risk of dizziness and low blood pressure.
- Avoid excessive sun exposure and use sunscreen, as this medication can increase sensitivity to sunlight.
- Regularly monitor your blood pressure at home if advised by your doctor.
- Stay hydrated, especially in hot weather or during exercise, but avoid excessive fluid intake unless directed by your doctor.
Available Forms & Alternatives
Dosing & Administration
Adult Dosing
Condition-Specific Dosing:
Pediatric Dosing
Dose Adjustments
Renal Impairment:
Hepatic Impairment:
Pharmacology
Mechanism of Action
Pharmacokinetics
Absorption:
Distribution:
Elimination:
Pharmacodynamics
Safety & Warnings
Side Effects
Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor or seek medical help right away:
Signs of an allergic reaction: rash, hives, itching, red, swollen, blistered, or peeling skin (with or without fever), wheezing, tightness in the chest or throat, trouble breathing, swallowing, or talking, unusual hoarseness, or swelling of the mouth, face, lips, tongue, or throat
Signs of high blood sugar: confusion, feeling sleepy, unusual thirst or hunger, frequent urination, flushing, fast breathing, or fruity-smelling breath
Signs of fluid and electrolyte problems: mood changes, confusion, muscle pain or weakness, fast or abnormal heartbeat, severe dizziness or fainting, increased thirst, seizures, feeling extremely tired or weak, decreased appetite, inability to urinate or changes in urine output, dry mouth, dry eyes, or severe nausea and vomiting
Signs of pancreas problems (pancreatitis): severe stomach pain, severe back pain, or severe nausea and vomiting
Signs of kidney problems: inability to urinate, changes in urine output, blood in the urine, or significant weight gain, dark urine, or yellow skin and eyes
Fever, chills, or sore throat
Unexplained bruising or bleeding
Feeling extremely tired or weak
Abnormal sensations such as burning, numbness, or tingling
Shortness of breath
Restlessness
Erectile dysfunction
Eye Problems
This medication can cause certain eye problems, which may lead to permanent vision loss if left untreated. If you experience eye problems, symptoms such as changes in vision or eye pain usually occur within hours to weeks of starting the medication. Contact your doctor immediately if you notice any of these signs.
Skin Cancer Risk
Rarely, people taking hydrochlorothiazide have developed certain types of skin cancer. To minimize this risk, protect your skin from the sun and follow your doctor's instructions for skin checks. If you notice any changes in the color or size of a mole, or any new or changing skin lump or growth, contact your doctor right away.
Other Side Effects
Like all medications, this drug can cause side effects. Although many people do not experience any side effects or only have mild ones, it is essential to discuss any concerns with your doctor. If you experience any of the following side effects, contact your doctor or seek medical help if they bother you or do not go away:
Constipation, diarrhea, upset stomach, nausea and vomiting, or decreased appetite
Stomach cramps
Dizziness, tiredness, or weakness
Headache
Reporting Side Effects
This is not an exhaustive list of possible side effects. If you have questions or concerns about side effects, contact your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Seek Immediate Medical Attention If You Experience:
- Severe dizziness or fainting
- Unusual muscle weakness or cramps
- Irregular or fast heartbeat
- Extreme thirst or dry mouth
- Nausea or vomiting that doesn't go away
- Signs of an allergic reaction (rash, itching, swelling, severe dizziness, trouble breathing)
- Sudden decrease in vision or eye pain (may indicate acute angle-closure glaucoma)
- Signs of high blood sugar (increased thirst, increased urination, hunger, blurred vision)
- Signs of gout (sudden, severe joint pain, swelling, redness, especially in the big toe)
Before Using This Medicine
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction you experienced.
A known sulfa allergy.
If you have difficulty urinating.
If you are currently taking dofetilide or lithium.
This list is not exhaustive, and it is crucial to discuss all your medications (including prescription, over-the-counter, natural products, and vitamins) and health issues with your doctor and pharmacist. They will help determine if it is safe to take this medication with your existing treatments and health conditions.
Remember, do not start, stop, or adjust the dosage of any medication without first consulting your doctor.
Precautions & Cautions
To minimize the risk of accidents, avoid driving and engaging in activities that require alertness until you understand how this medication affects you. When changing positions, such as standing up from a sitting or lying down position, do so slowly to reduce the likelihood of dizziness or fainting. Be cautious when navigating stairs to avoid falls.
Regular blood tests and other laboratory evaluations are crucial to monitor your health while taking this medication. Your doctor will schedule these tests to assess your condition and make any necessary adjustments to your treatment plan.
Be aware that this medication can cause increases in cholesterol and triglyceride levels. If you have a history of high cholesterol or triglycerides, discuss this with your doctor to determine the best course of action. Additionally, if you have diabetes, it is crucial to closely monitor your blood sugar levels to avoid any potential complications.
Regularly check your blood pressure as instructed by your doctor, as this medication can affect your blood pressure readings. It is also important to inform all your healthcare providers and laboratory personnel that you are taking this medication, as it may interfere with certain laboratory tests.
If you have high blood pressure, consult with your doctor before taking any over-the-counter (OTC) products that may increase your blood pressure, such as cough or cold medications, diet pills, stimulants, non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen or naproxen, and certain natural products or aids.
As this medication is a potent diuretic, it can lead to excessive loss of water and electrolytes (such as potassium) in the blood, resulting in severe health problems. Your doctor will closely monitor your condition and adjust your dosage as needed to minimize this risk.
If you are following a low-salt or salt-free diet, discuss this with your doctor to ensure safe and effective treatment. It is also important to consult with your doctor before consuming alcohol, using marijuana or other cannabis products, or taking prescription or OTC medications that may cause drowsiness.
Inform your doctor if you experience excessive sweating, fluid loss, vomiting, or diarrhea, as these conditions can lead to low blood pressure. If you are taking cholestyramine or colestipol, consult with your pharmacist about the best way to take these medications with this drug, and be aware of the potential for gout attacks.
If you have a history of lupus, this medication can cause your condition to become active or worsen. Immediately report any new or worsening symptoms to your doctor. Additionally, this medication can increase your sensitivity to the sun, making you more prone to sunburn. Take necessary precautions when spending time outdoors, and inform your doctor if you experience any unusual sunburn or sensitivity.
As you age, your risk of experiencing side effects from this medication may increase. If you are 65 or older, use this medication with caution and under the close supervision of your doctor.
Finally, if you are pregnant, planning to become pregnant, or breastfeeding, it is essential to discuss the potential benefits and risks of this medication with your doctor to ensure the best possible outcome for you and your baby.
Overdose Information
Overdose Symptoms:
- Dehydration
- Electrolyte imbalance (especially hypokalemia, hyponatremia)
- Hypotension (low blood pressure)
- Dizziness, weakness, confusion
- Nausea, vomiting
- Cardiac arrhythmias (due to electrolyte imbalance)
What to Do:
Seek immediate medical attention. Call 911 or Poison Control at 1-800-222-1222. Treatment is supportive and symptomatic, focusing on correcting fluid and electrolyte imbalances.
Drug Interactions
Major Interactions
- Lithium (increased lithium levels and toxicity)
- Corticosteroids, ACTH (enhanced electrolyte depletion, particularly hypokalemia)
- Non-steroidal anti-inflammatory drugs (NSAIDs) (reduced diuretic and antihypertensive effects, risk of renal impairment)
- Digoxin (hypokalemia and hypomagnesemia can increase digoxin toxicity)
- Cholestyramine, Colestipol (reduced absorption of hydrochlorothiazide)
- Diazoxide (enhanced hyperglycemic and hypotensive effects)
- Neuromuscular blocking agents (e.g., tubocurarine) (potentiated effect due to hypokalemia)
Moderate Interactions
- Antidiabetic agents (oral agents and insulin) (may require dosage adjustment due to decreased glucose tolerance)
- Other antihypertensive agents (additive hypotensive effect)
- Alcohol, barbiturates, narcotics (additive orthostatic hypotension)
- Pressor amines (e.g., norepinephrine) (possible decreased arterial responsiveness)
- Amphotericin B, Carbenoxolone (increased risk of hypokalemia)
- Calcium salts, Vitamin D (increased risk of hypercalcemia)
- Allopurinol (increased risk of hypersensitivity reactions to allopurinol)
- Cyclosporine (increased risk of hyperuricemia and gouty complications)
Minor Interactions
- Methenamine (reduced efficacy of methenamine due to urinary alkalinization)
Monitoring
Baseline Monitoring
Rationale: To establish baseline levels and identify pre-existing imbalances, as hydrochlorothiazide can cause hypokalemia, hyponatremia, hypomagnesemia, and hypercalcemia.
Timing: Prior to initiation of therapy.
Rationale: To assess kidney function, as hydrochlorothiazide is renally eliminated and its efficacy is reduced in severe renal impairment.
Timing: Prior to initiation of therapy.
Rationale: To establish baseline and guide initial dosing for hypertension.
Timing: Prior to initiation of therapy.
Rationale: To establish baseline, as hydrochlorothiazide can cause hyperglycemia.
Timing: Prior to initiation of therapy, especially in patients with diabetes or risk factors.
Rationale: To establish baseline, as hydrochlorothiazide can cause hyperuricemia.
Timing: Prior to initiation of therapy, especially in patients with a history of gout.
Routine Monitoring
Frequency: Periodically, especially during dose titration, intercurrent illness, or concomitant use of interacting drugs. Typically 1-2 weeks after initiation/dose change, then every 1-3 months for stable patients.
Target: Potassium: 3.5-5.0 mEq/L; Sodium: 135-145 mEq/L; Magnesium: 1.7-2.2 mg/dL; Calcium: 8.5-10.2 mg/dL
Action Threshold: Potassium < 3.0 mEq/L (consider supplementation or dose reduction); Sodium < 130 mEq/L (investigate cause, consider discontinuation); Significant deviations from normal ranges.
Frequency: Periodically, especially in elderly patients or those with pre-existing renal impairment. Typically every 3-6 months.
Target: Within normal limits for age and baseline.
Action Threshold: Significant increase in BUN/creatinine (e.g., >20-30% above baseline) or eGFR < 30 mL/min (consider discontinuation).
Frequency: Regularly, at each clinic visit or as directed by physician.
Target: Individualized, e.g., <130/80 mmHg for most adults.
Action Threshold: Failure to achieve target BP, or symptomatic hypotension.
Frequency: Periodically, especially in diabetic patients. Typically every 3-6 months.
Target: Individualized, e.g., HbA1c < 7%.
Action Threshold: Significant increase in blood glucose or worsening glycemic control.
Frequency: Periodically, especially in patients with a history of gout. Typically every 6-12 months.
Target: Within normal limits or individualized for gout patients.
Action Threshold: Significant increase in uric acid or onset of gout symptoms.
Symptom Monitoring
- Dizziness or lightheadedness (especially upon standing)
- Muscle cramps or weakness
- Excessive thirst or dry mouth
- Nausea or vomiting
- Unusual tiredness or weakness
- Irregular heartbeat
- Signs of gout (joint pain, swelling, redness)
- Signs of hyperglycemia (increased thirst, urination, hunger)
- Skin rash or photosensitivity
Special Patient Groups
Pregnancy
Generally not recommended for routine use in healthy pregnant women with mild edema or gestational hypertension due to potential for reduced plasma volume and placental hypoperfusion. Use only if clearly needed and benefits outweigh risks. Older classification was Category B.
Trimester-Specific Risks:
Lactation
Excreted in breast milk. May suppress lactation. Use with caution, and monitor infant for potential adverse effects (e.g., electrolyte imbalance). Consider alternative if possible, especially in preterm infants or those with underlying conditions.
Pediatric Use
Dosing is weight-based. Use with caution, especially in infants, due to higher risk of electrolyte imbalances. Not recommended for neonates.
Geriatric Use
More susceptible to dose-dependent adverse effects, particularly electrolyte imbalances (hypokalemia, hyponatremia) and orthostatic hypotension. Start with lower doses and monitor closely.
Clinical Information
Clinical Pearls
- Hydrochlorothiazide is a first-line agent for hypertension, especially in black patients and those with edema.
- Take in the morning to avoid nocturia (nighttime urination).
- Monitor electrolytes (especially potassium) regularly, as hypokalemia is a common side effect.
- Can cause hyperuricemia and precipitate gout attacks in susceptible individuals.
- May cause photosensitivity; advise patients to use sunscreen and protective clothing.
- Less effective than loop diuretics in patients with significant renal impairment (CrCl < 30 mL/min).
Alternative Therapies
- Loop diuretics (e.g., Furosemide, Torsemide) for more potent diuresis or severe renal impairment
- Potassium-sparing diuretics (e.g., Spironolactone, Amiloride) for potassium conservation
- ACE inhibitors (e.g., Lisinopril, Enalapril)
- Angiotensin Receptor Blockers (ARBs) (e.g., Valsartan, Losartan)
- Calcium Channel Blockers (e.g., Amlodipine, Diltiazem)
- Beta-blockers (e.g., Metoprolol, Atenolol)