How does this medication work? What will it do for me?
This is a combination product that contains 2 medications used to lower high blood pressure (hypertension), losartan and hydrochlorothiazide.
Losartan belongs to the class of medications called angiotensin II receptor blockers. They help to lower blood pressure by relaxing blood vessels. Hydrochlorothiazide belongs to the class of medications called diuretics or "water pills." It helps control blood pressure by getting rid of excess salt and water.
This combination medication is prescribed when your doctor feels it is appropriate for you to be taking both medications. It is usually prescribed after a person's blood pressure is stabilized on losartan and hydrochlorothiazide taken individually.
It usually takes 3 to 6 weeks to see the full effects of this medication.
This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.
Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.
Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.
What form(s) does this medication come in?
How should I use this medication?
Once the dose of each medication (losartan and hydrochlorothiazide) has been determined, the combination tablets can be started. The recommended dose is one tablet once daily. The maximum dose is one tablet per day.
The medication can be taken with or without food, but should be taken consistently. This means that if you usually take it with food, continue to take it with food, and if you usually take it without food, continue to take it without food.
Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.
It is important that this medication be taken exactly as prescribed by your doctor. If you miss a dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.
Store this medication at room temperature, protect it from light and moisture, and keep it out of the reach of children.
Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.
Who should NOT take this medication?
Do not take losartan - hydrochlorothiazide if you:
- are allergic to losartan, hydrochlorothiazide, or any ingredient of the medication
- are allergic to sulfa (sulfonamide) medications (e.g., sulfamethoxazole)
- are pregnant or breast-feeding
- have anuria (are able to pass little or no urine)
- have diabetes or kidney disease and are taking aliskiren
- have been diagnosed with hereditary angioedema
- have galactose intolerance (a rare hereditary condition)
What side effects are possible with this medication?
Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.
The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.
The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.
Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.
- abdominal pain
- back or leg pain
- decreased appetite
- decreased sexual interest or ability
- dizziness when rising from a sitting or lying position
- increased frequency of sinus infections or nasal congestion
- muscle cramps
- pins and needles sensation
- sensitivity to the sun
- sexual difficulties
- swollen glands in the mouth
- taste alterations
- trouble sleeping
Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.
Check with your doctor as soon as possible if any of the following side effects occur:
- discoloured patches or lumps on the skin that change slowly over time
- pounding, rapid heartbeat
- rash, red patches under the skin
- signs of anemia (low red blood cells; e.g., dizziness, pale skin, unusual tiredness or weakness, shortness of breath)
- signs of bleeding (e.g., unusual nosebleeds, bruising, blood in urine, coughing blood, bleeding gums, cuts that don't stop bleeding)
- signs of electrolyte changes (e.g., irregular heartbeat, muscle weakness, general feeling of being unwell, lack of energy, confusion, muscle pain or cramps, drowsiness)
- signs of gout (e.g., joint pain, swelling and warmth of joints)
- signs of infections (symptoms may include fever or chills, severe diarrhea, shortness of breath, prolonged dizziness, headache, stiff neck, weight loss, or listlessness)
- signs of kidney problems (e.g., decreased urination, nausea, vomiting, swelling of the feet and ankles)
- signs of liver damage (yellowing of skin or whites of eyes, abdominal pain, loss of appetite, brown urine, light-coloured stools, tiredness, or weakness)
- signs of low blood pressure such as dizziness, lightheadedness, or fainting
- signs of muscle damage (e.g., unexplained muscle pain, tenderness or weakness, or brown or discoloured urine)
- skin rash (especially if you also have joint pain)
- swelling legs, ankles, or hands
- symptoms of high blood sugar (e.g., frequent urination, increased thirst, excessive eating, unexplained weight loss, poor wound healing, infections, fruity breath odour)
- symptoms of increased pressure in the eyes (e.g., decreased or blurred vision, eye pain, red eye, swelling of the eye)
- vision changes (blurred vision, increased eye pressure, eye pain)
Stop taking the medication and seek immediate medical attention if any of the following occur:
- chest pain
- signs of a serious allergic reaction (swelling of face or throat, hives, difficulty breathing)
- severe skin rash, including skin blistering and peeling (possibly with headache, fever, coughing, or aching before the rash begins)
- signs of pancreatitis (e.g., abdominal pain on the upper left side, back pain, nausea, fever, chills, rapid heartbeat, swollen abdomen)
Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.
Are there any other precautions or warnings for this medication?
Before you begin taking a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should take this medication.
Allergic reaction: Some people who are allergic to sulfonamide medications also experience allergic reactions to hydrochlorothiazide. Before you take this medication, inform your doctor about any previous adverse reactions you have had to medications, especially to sulfonamide antibiotics or diabetes medications. Contact your doctor at once if you experience signs of an allergic reaction, such as skin rash, itching, difficulty breathing or swelling of the face and throat.
Cholesterol: Cholesterol and triglyceride levels may increase when taking hydrochlorothiazide. Talk to your doctor about whether you will need to have your cholesterol levels tested while you are taking this medication. If you have increased cholesterol or triglyceride levels, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.
Diabetes: Hydrochlorothiazide may make it more difficult for people with diabetes to control their blood sugar levels. High blood sugar may occur, glucose tolerance may change, and diabetes may worsen. A dose adjustment of diabetes medications, including insulin, may be required. If you have diabetes, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.
Electrolytes: The use of hydrochlorothiazide can reduce the levels of electrolytes such as potassium, sodium, magnesium, and chloride, and increase the levels of calcium. Your doctor will periodically check to see if these levels are in balance and a potassium supplement may be recommended. Warning signs or symptoms of fluid and electrolyte imbalance include:
- dryness of mouth
- low blood pressure
- muscle pains or cramps
- muscular fatigue
- nausea and vomiting
- racing heartbeat
Gout: An acute gout attack may occur in some patients taking losartan - hydrochlorothiazide as a result of high levels of uric acid in the blood. Symptoms of an acute gout attack include sudden pain, swelling, and stiffness in the affected joint, often the big toe. You may also experience a fever. If this is your first attack, seek medical attention as soon as possible. If you have had gout attacks before, follow your doctor's instructions for dealing with the attack.
Heart Problems: Losartan – hydrochlorothiazide can cause fluid to build up in the body, increasing the work the heart must do to keep the blood circulating. If you have had a recent heart attack, or you have congestive heart failure, taking losartan – hydrochlorothiazide can make symptoms of these heart conditions worse. If you have a history of heart problems, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.
Kidney function: Losartan – hydrochlorothiazide can cause changes to kidney function that may result in decreased kidney function, kidney failure, or possibly death. This is particularly likely for those who already have kidney problems. Certain people have experienced changes in kidney function (e.g., people with narrowed blood vessels in their kidneys, or those with severe congestive heart failure). The use of diuretics (water pills), nonsteroidal anti-inflammatory drugs (NSAIDs), or aliskiren may further increase risk of kidney problems for people already at risk for this problem. If you have reduced kidney function, renal artery stenosis (narrowing of blood vessels in the kidneys), or congestive heart failure, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.
Liver function: Liver disease or reduced liver function may cause this medication to build up in the body, causing side effects. People with reduced liver function may need a lower-than-normal dose of losartan; therefore, it may be necessary to use the components of the combination product separately. If you have reduced liver function or liver disease, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. This medication is not recommended for people with severe liver impairment.
This medication may also cause a decrease in liver function. If you experience symptoms of liver problems such as fatigue, feeling unwell, loss of appetite, nausea, yellowing of the skin or whites of the eyes, dark urine, pale stools, abdominal pain or swelling, and itchy skin, contact your doctor immediately.
Low blood pressure: Occasionally, a greater-than-expected drop in blood pressure occurs after taking this medication. It is more likely to occur if you are taking additional diuretics (water pills), have reduced salt intake, are on dialysis, or are experiencing diarrhea or vomiting. Blood pressure should be monitored more often in these situations. To reduce the risk of dizziness, those with low blood pressure or those just starting to take this medication should stand or sit up slowly when getting up from a lying down or sitting position.
If low blood pressure causes you to faint or feel lightheaded, contact your doctor.
Excessive sweating and lack of fluid intake may lead to an excessive fall in blood pressure because of reduced fluid in your blood vessels. Vomiting or diarrhea may also lead to a fall in blood pressure. Consult your doctor if you feel your blood pressure is too low.
Lupus: There have been reports of a worsening or activation of lupus in people taking hydrochlorothiazide. If you have lupus, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.
Potassium levels: Increases in blood levels of potassium occur for approximately 2% of people who take this medication. This rarely causes problems, but your doctor will likely want to monitor your potassium levels through blood tests. Avoid using salt substitutes that contain potassium while you are taking losartan - hydrochlorothiazide.
Sensitivity to sunlight: This medication may increase the sensitivity of the skin to sunlight, increasing the risk of sunburn. Avoid exposure to sunlight for long periods of time, particularly between the hours of 10 am and 2 pm, while you are taking this medication. Wear a broad-spectrum sunscreen and lip balm with an SPF of 30 or higher. If you notice any unusual skin rash or peeling, contact your doctor immediately.
Skin cancer: Recent reviews of hydrochlorothiazide has connected long term use of the medication with an increased risk of developing non-melanoma skin cancer. This often appears as a lump or discoloured patch of skin that slowly changes appearance or size. Check your skin regularly for unusual growths or discolouration and report any changes to your doctor as soon as possible. Talk to your doctor about any concerns you may have.
Vision changes: Hydrochlorothiazide occasionally causes vision changes including increased eye pressure (glaucoma) and myopia (nearsightedness). If you experience any eye symptoms, such as pain or change in vision, contact your doctor as soon as possible.
Pregnancy: Losartan may cause severe harm to an unborn fetus if it is taken by the mother during pregnancy. Pregnant women should not take this medication. If you become pregnant while taking this medication, stop taking it immediately and call your doctor.
Breast-feeding: It is not known if losartan passes into breast milk. Hydrochlorothiazide does pass into breast milk. If you are a breast-feeding mother and are taking this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.
Children: The safety and effectiveness of using this medication have not been established for children. This medication is not recommended for children.
Seniors: Seniors may be more sensitive to the effects of this medication and may experience more side effects.
What other drugs could interact with this medication?
There may be interaction between losartan - hydrochlorothiazide and any of the following:
- alpha-adrenergic blocking agents (e.g., alfuzosin, doxazosin, prazosin, terazosin)
- alpha-agonists (e.g., clonidine, methyldopa)
- amphetamines (e.g., dextroamphetamine, lisdexamfetamine)
- angiotensin converting enzyme inhibitors (ACEIs; captopril, enalapril, ramipril)
- other angiotensin receptor blockers (ARBs; e.g., candasartan, irbesartan, valsartan)
- antihistamines (e.g., cetirizine, doxylamine, diphenhydramine, hydroxyzine, loratadine)
- antipsychotics (e.g., chlorpromazine, clozapine, haloperidol, olanzapine, quetiapine, risperidone)
- "azole" antifungals (e.g., itraconazole, ketoconazole, voriconazole)
- barbiturates (e.g., butalbital, phenobarbital)
- beta-blockers (e.g., atenolol, carvedilol, propranolol)
- beta 2 agonists (e.g., salbutamol, formoterol, terbutaline)
- calcium carbonate, calcium citrate
- calcium channel blockers (e.g., amlodipine, diltiazem, nifedipine, verapamil)
- inhaled corticosteroids (e.g., budesonide, ciclesonide, fluticasone)
- oral corticosteroids (e.g., dexamethasone, hydrocortisone, prednisone)
- diabetes medications (e.g., chlorpropamide, glyburide, insulin, metformin, repaglinide, rosiglitazone)
- diuretics (water pills; e.g., furosemide, hydrochlorothiazide, triamterene)
- HIV non-nucleoside reverse transcriptase inhibitors (NNRTIs; e.g., delavirdine, efavirenz, etravirine, nevirapine)
- low molecular weight heparins (e.g., dalteparin, enoxaparin, tinzaparin)
- medications that increase blood levels of potassium (e.g., potassium chloride, salt substitutes containing potassium)
- milk thistle
- monoamine oxidase inhibitors (MAOIs; e.g., moclobemide, phenelzine, rasagiline, selegiline, tranylcypromine)
- multivitamins/minerals with ADE
- narcotic pain relievers (e.g., codeine, fentanyl, morphine)
- nitrates (e.g., nitroglycerin, isosorbide dinitrate, isosorbide mononitrate)
- nonsteroidal anti-inflammatory drugs (NSAIDs; e.g., ibuprofen, naproxen)
- phosphodiesterase 5 inhibitors (e.g., sildenafil, tadalafil, vardenafil)
- St. John's wort
- selective serotonin reuptake inhibitors (SSRIs; e.g., citalopram, duloxetine, fluoxetine, paroxetine, sertraline)
- sodium phosphates
- sulfonamide antibiotics (e.g., sulfadiazine, sulfamethoxazole, sulfisoxazole)
- tricyclic antidepressants (e.g., amitriptyline, clomipramine, desipramine, trimipramine)
- vitamin D
If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:
- stop taking one of the medications,
- change one of the medications to another,
- change how you are taking one or both of the medications, or
- leave everything as is.
An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.
Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.
All material copyright MediResource Inc. 1996 – 2023. Terms and conditions of use. The contents herein are for informational purposes only. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Source: www.medbroadcast.com/drug/getdrug/ACT-LosartanHCT