PMS-Hydrochlorothiazide (Pharmascience, 25 mg, 50 mg, 12.5 mg): Uses, Side Effects and Dosage

What pms-HYDROCHLOROTHIAZIDE is used for:

pms-HYDROCHLOROTHIAZIDE is used in adults (18 to 65 years of age), infants and children (0 to 12 years of age):

• to treat fluid retention (edema) caused by heart failure, liver disease, kidney disease, premenstrual tension, or corticosteroid and estrogen therapy.
• alone or in combination with other medications to treat high blood pressure.
• to treat pregnancy-induced high blood pressure.

How pms-HYDROCHLOROTHIAZIDE works:

pms-HYDROCHLOROTHIAZIDE belongs to a group of medicines called diuretics (also known as “water pills”). It works by causing your body to get rid of excess water and salt from your body through your urine. This helps to reduce swelling (edema) and lowers high blood pressure.

This medicine does not cure high blood pressure or edema. It helps to control them. Therefore, it is important to continue taking pms-HYDROCHLOROTHIAZIDE regularly even if you feel fine.

The ingredients in pms-HYDROCHLOROTHIAZIDE are:

Medicinal ingredient: Hydrochlorothiazide

Non-medicinal ingredients:

• 12.5 mg tablets: Alginic acid, colloidal silicon dioxide, FD&C Yellow No. 6 Aluminum Lake, magnesium stearate, microcrystalline cellulose and sodium carboxymethylcellulose.
• 25 mg and 50 mg tablets: Colloidal silicon dioxide, corn starch, dibasic calcium phosphate, FD&C Yellow No. 6 Lake, lactose monohydrate, magnesium stearate and pregelatinized starch.

pms-HYDROCHLOROTHIAZIDE comes in the following dosage form:

Tablets: 12.5 mg, 25 mg, and 50 mg

Do not use pms-HYDROCHLOROTHIAZIDE if:

• you are allergic to hydrochlorothiazide or to any of the other ingredients in pms-HYDROCHLORITHIAZIDE.
• you are allergic to any sulfonamide-derived drugs (sulfa drugs); most of them have a medicinal ingredient that ends in “-MIDE”.
• You have difficulty urinating or produce no urine.
• you are breast-feeding or planning to breast-feed.
• you have severe, worsening kidney problems.

• You have one of the following rare hereditary diseases:

  • Galactose intolerance
  • Lapp lactase deficiency
  • Glucose-galactose malabsorption. Because pms-HYDROCHLOROTHIAZIDE tablets contain lactose.

To help avoid side effects and ensure proper use, talk to your healthcare professional before you take pms-HYDROCHLOROTHIAZIDE. Talk about any health conditions or problems you may have, including if you:

• are allergic to penicillin, used to treat bacterial infections.
• have diabetes.
• have liver or kidney problems.
• have lupus.
• have high levels of uric acid in the blood or have gout.
• have a history of allergies or bronchial asthma.
• are dehydrated or suffer from excessive vomiting, diarrhea, or sweating.
• have had or are planning to have a procedure called sympathectomy (cutting or blocking a nerve).
• are pregnant, think you might be pregnant or planning on becoming pregnant.

• have a greater chance of developing skin cancer because you:

  • had skin cancer or have a family history of skin cancer
  • have light-coloured skin
  • sunburn easily
  • take medications to suppress your immune system
• have had breathing or lung problems (including inflammation or fluid in the lungs) in the past following the use of medication containing hydrochlorothiazide. If you experience any severe shortness of breath or difficulty breathing after taking pms-HYDROCHLOROTHIAZIDE, stop the medication and seek medical attention immediately.

• are taking any of the following medications:

  • corticosteroids, used to treat joint pain and swelling
  • adrenocorticotropic hormone (ACTH), used to treat diseases such as nephrotic syndrome or collagen diseases and in diagnostic tests
  • lithium, used to treat bipolar disorder
  • digoxin, used to treat various heart conditions

Other warnings you should know about:

Diet: Taking pms-HYDROCHLOROTHIAZIDE may lead to increased removal of potassium from your body. If you are taking pms-HYDROCHLOROTHIAZIDE for an extended period of time, your healthcare professional may monitor your potassium levels and recommend that you eat a diet rich in potassium. They may also recommend that you take potassium supplements, especially if you have been prescribed high doses of pms-HYDROCHLOROTHIAZIDE.

Risk of skin cancer: pms-HYDROCHLOROTHIAZIDE contains hydrochlorothiazide. Treatment with hydrochlorothiazide may increase the risk of developing non-melanoma skin cancer. The risk is higher if you have been taking pms-HYDROCHLOROTHIAZIDE for many years (more than 3) or at a high dose.

While taking pms-HYDROCHLOROTHIAZIDE:

• Make sure to regularly check your skin for any new lesions. Check areas that are most exposed to the sun, such as the face, ears, hands, shoulders, upper chest and back.
• Limit your exposure to the sun and to indoor tanning. Always use sunscreen (SPF-30 or higher) and wear protective clothing when going outside.
• Talk to your doctor immediately if you get more sensitive to the sun or UV light or if you develop an unexpected skin lesion (such as a lump, bump, sore, or patch) during the treatment.

Eye problems: Hydrochlorothiazide in pms-HYDROCHLOROTHIAZIDE can cause sudden eye disorders:

• Choroidal effusion: an abnormal building of liquid in your eye that may result in vision changes
• Myopia: sudden nearsightedness or blurred vision
• Glaucoma: an increased pressure in your eyes, eye pain. If left untreated, it may lead to permanent vision loss. If your vision changes, stop taking pms-HYDROCHLOROTHIAZIDE and seek immediate medical help. These eye disorders are related and can develop within hours to weeks of starting pms-HYDROCHLOROTHIAZIDE.

Driving and using machines:

Before you perform tasks, which may require special attention, wait until you know how you respond to pms-HYDROCHLOROTHIAZIDE. Dizziness, light-headedness, or fainting can especially occur after the first dose and when the dose is increased.

Pregnancy and breast-feeding:

• pms-HYDROCHLOROTHIAZIDE is not recommended during pregnancy as it may harm an unborn child. You and your healthcare professional will decide whether the potential benefits of taking pms-HYDROCHLOROTHIAZIDE outweigh the potential risks to your unborn child. If you discover that you are pregnant during treatment, tell your healthcare professional right away.
• pms-HYDROCHLOROTHIAZIDE passes into breast milk. You and your healthcare professional should decide if you will take pms-HYDROCHLOROTHIAZIDE or breast-feed. You should not do both.

Check-ups and testing:

• Your healthcare professional may do tests before, during and after your treatment. These tests may be used to monitor the health of your kidneys, liver and thyroid, the levels of electrolytes in your blood (potassium, calcium, chloride, sodium), and your blood pressure.
• Your healthcare professional may stop your treatment with pms-HYDROCHLOROTHIAZIDE before performing tests to assess the health of your parathyroid glands.

Tell your healthcare professional about all the medicines you take, including any drugs, vitamins, minerals, natural supplements or alternative medicines.

The following may interact with pms-HYDROCHLOROTHIAZIDE:

• Other medicines used to lower high blood pressure such as guanethidine, methyldopa, beta blockers, ACE inhibitors, ARBs, beta blockers, vasodilators, calcium channel blockers and direct renin inhibitors.
• Alcohol, barbiturates (sleeping pills), or narcotics (strong pain medications). They may cause low blood pressure and dizziness when you go from lying or sitting to standing up.
• Amphotericin B, an antifungal medication.
• Anticancer medications, such as cyclophosphamide and methotrexate.
• Antidepressants, in particular selective serotonin reuptake inhibitors (SSRIs), such as citalopram, escitalopram, and sertraline.
• Antidiabetic medications, such as insulin and oral medicines.
• Bile acid resins, used to lower cholesterol.
• Calcium or vitamin D supplements.
• Corticosteroids, used to treat joint pain and swelling.
• Digoxin, used to treat various heart conditions.
• Medications that slow down or speed up your bowels, such as atropine, metoclopramide, and domperidone.
• Medications used to treat epilepsy, such as carbamazepine and topiramate.
• Gout medications, such as allopurinol and probenecid.
• Lithium, used to treat bipolar disease.
• Non-steroidal anti-inflammatory drugs (NSAIDs), used to reduce pain and swelling such as ibuprofen, naproxen, acetylsalicylic acid and celecoxib.
• Skeletal muscle relaxants used to relieve muscle spasms, such as tubocurare.

• Adrenocorticotropic hormone (ACTH), which may be used to treat diseases such as

  nephrotic syndrome or collagen diseases and in diagnostic tests.

How to take pms-HYDROCHLOROTHIAZIDE:

Take pms-HYDROCHLOROTHIAZIDE:

• exactly as your healthcare professional has told you to.
• at about the same time everyday.

• with or without food. If it causes an upset stomach, take it with food or milk.

In your diet, be sure to include foods that contain potassium such as tomatoes, bananas, and beans.

Usual dose:

Adults:

• To treat fluid retention (edema): 50 mg to 100 mg once or twice a day. You may be asked to take pms-HYDROCHLOROTHIAZIDE every other day or 3 to 5 days a week to avoid certain side effects. Follow your healthcare professional’s instructions carefully.
• To treat pregnancy-induced high blood pressure: 100 mg once a day. If your condition is severe, your dose may be increased briefly to 200 mg daily in divided doses. Your doses may be prescribed once a day or every 4 days.
• To treat premenstrual tension with edema: 25 mg to 50 mg once or twice a day from the day you first experience symptoms until the start of your menstruation (period).
• To treat high blood pressure: 50 mg or 100 mg a day as a single dose or in divided doses. Your healthcare professional may increase or decrease your dose depending on your condition and how you respond to pms-HYDROCHLOROTHIAZIDE.

Infants and children:

• Your child’s healthcare professional will determine the right dose based on your child’s weight. Follow their instructions carefully.

• The usual dosage range is:

  • Infants (0 to 2 years of age): 12.5 mg to 37.5 mg daily in two doses.
  • Children (2 to 12 years of age): 37.5 mg to 100 mg daily in two doses.

Overdose:

Symptoms of an overdose with pms-HYDROCHLOROTHIAZIDE:

• Body producing and passing more urine than normal
• Low electrolyte levels in the blood, which may cause you to feel weak, dizzy, confused, tired, have muscle pain or cramps, or vomit
• Dehydration, including dry mouth, feeling thirsty and low urine output
• Low blood pressure that can lead to shock (rapid breathing or heartbeat, pale skin, cold clammy skin)
• A decline in brain function, including coma, in patients with severe liver problems (i.e., cirrhosis)
• Gastrointestinal problems
• Sudden change in mental status (delirium) or mental confusion
• Lack of energy or feeling restless
• Convulsions

Missed dose:

If you miss a dose of your medication, skip your missed dose and take the next dose at your usual scheduled time. Do not double your dose to make up for a missed dose.

Possible side effects from using pms-HYDROCHLOROTHIAZIDE:

These are not all the possible side effects you may have when taking pms-HYDROCHLOROTHIAZIDE. If you experience any side effects not listed here, tell your healthcare professional.

Side effects with pms-HYDROCHLOROTHIAZIDE may include:

• dizziness or feeling like you are spinning (vertigo)
• tingling or “pins and needles” sensation of the skin
• headache
• yellow hue or tint in your vision
• weigh loss
• upset stomach
• nausea or vomiting
• purple spots, skin rash, hives
• fever
• muscle spasms
• weakness
• restlessness
• increased sensitivity to sunlight
• enlargement of the glands in your mouth
• constipation or diarrhea

Serious side effects and what to do about them

If you have a troublesome symptom or side effect that is not listed here or becomes bad enough to interfere with your daily activities, tell your healthcare professional.

Reporting side effects

Storage:

• Store between 15°C and 30°C away from heat and light.
• Keep out of reach and sight of children.

If you want more information about pms-HYDROCHLOROTHIAZIDE:

• Talk to your healthcare professional
• Find the full product monograph that is prepared for healthcare professionals and includes the Patient Medication Information by visiting the Health Canada Drug Product Database website (https://www.canada.ca/en/health-canada/services/drugs-health-products/drug-products/drug-product-database.html); the manufacturer’s website www.pharmascience.com; or by calling 1-888-550-6060.

Date of Authorization: 2026-10-20