Drug information of Indapamide

Mechanism of effect

Indapamide blocks the slow component of delayed rectifier potassium current (IKs) without altering the rapid component (IKr) or the inward rectifier current. Specifically it blocks or antagonizes the action the proteins KCNQ1 and KCNE1.

Indapamide is also thought to stimulate the synthesis of the vasodilatory hypotensive prostaglandin PGE2.

Pharmacodynamic

Indapamide is an antihypertensive and a diuretic. It contains both a polar sulfamoyl chlorobenzamide moiety and a lipid- soluble methylindoline moiety. Indapamide bears a structural similarity to the triazide diuretics which are known to decrease vascular smooth muscle reactivity. However, it differs chemically from the thiazides in that it does not possess the thiazide ring system and contains only one sulfonamide group.

 Indapamide appears to cause vasodilation, probably by inhibiting the passage of calcium and other ions (sodium, potassium) across membranes. This same effect may cause hypokalcemia in susceptible individuals. Indapamide has also been shown to cause uterine myometrial relaxation in experimental animals. Overall, indapamide has an extra-renal antihypertensive action resulting in a decrease in vascular hyperreactivity and a reduction in total peripheral and arteriolar resistance.

Pharmacokinetics

• Half-Life: 14-25 hr
• Onset: 1-3 hr
• Duration: 8-12 hr
• Peak Plasma Time: 2 hr
• Bioavailability: 93%
• Protein Bound: 71-79%
• Vd: 24-25 L
• Metabolism: Liver
• Metabolites: 19 metabolites, not identified, activity unknown
• Excretion: Urine (70% with 7% unchanged), feces (23%)

Drug indications

High Blood Pressure , fluid retention

Dosage

Adult

Edema

2.5 mg PO qDay initially; may increase to 5 mg qDay

Hypertension

1.25 mg PO qAM initially; may increase at 4-week intervals up to 5 mg qAM

Pediatric

Safety & efficacy not established

Drug contraindications

Anuria , hypersensitivity to this drug , hypersensitivity to sulfonamides

Side effects

Headache , nausea , dizziness , vomiting , Blurred vision , flushing , vertigo , asthenia , palpitations , anorexia , itching , tiredness , Restlessness , lightheadedness , Rash , Rhinorrhea , Electrolyte abnormalities

Interactions

Amitriptyline , Amiodarone , Epinephrine , Erythromycin , Ofloxacin , Ondansetron , Itraconazole , Imipramine , Paroxetine , perphenazine , Promethazine , Posaconazole , Pimozide , Trazodone , Tretinoin , Trifluoperazine , Trimipramine , Thioridazine , Desipramine , Doxepin , Disopyramide , Risperidone , Sotalol , Cisapride , Fluvoxamine , Fluoxetine , Fluconazole , Levofloxacin , Maprotiline , Methadone , Moxifloxacin , Nortriptyline , Nilotinib , Haloperidol , Venlafaxine , Voriconazole , Ketoconazole , Clarithromycin , Chlorpromazine , Clomipramine , Flecainide , Ranolazine , Trimethoprim , Pentamidine , Prochlorperazine , Quinidine , Amoxapine , isocarboxazid , Ziprasidone , protriptyline , Dolasetron , Telithromycin , Droperidol , Sertindole , Procainamide , Mefloquine , Octreotide acetate , Fluphenazine , formoterol , aminolevulinic acid oral , Aminolevulinic acid topical , Paliperidone , Treprostinil , cosyntropin , Calcitriol (topical) , vemurafenib , Terfenadine , Foscarnet , tropisetron

Alerts

Hypotension, DM, fluid or electrolyte imbalance, hyperuricemia or gout, SLE, liver disease, renal disease

Avoid concurrent use with lithium

More effective in impaired renal function than thiazides

No effect on lipids/cholesterol

Severe cases of hyponatremia, accompanied by hypokalemia have been reported with recommended doses in elderly females

Points of recommendation

Avoid driving and doing other tasks or actions that call for you to be alert until you see how indapamide affects you.

To lower the chance of feeling dizzy or passing out, rise slowly if you have been sitting or lying down. Be careful going up and down stairs.

If you have high blood sugar (diabetes), you will need to watch your blood sugar closely.

Have your blood pressure checked often. Talk with your doctor.

Have blood work checked as you have been told by the doctor. Talk with the doctor.

This medicine may affect certain lab tests. Tell all of your health care providers and lab workers that you take indapamide.

This medicine is a strong fluid-lowering drug (diuretic). Sometimes too much water and major elements (potassium) in the blood may be lost. This can lead to serious health problems. Your doctor will follow you closely to change the dose to match your body's needs.

You may need extra potassium. Talk with your doctor.

If you are on a low-salt or salt-free diet, talk with your doctor.

If you are taking indapamide and have high blood pressure, talk with your doctor before using OTC products that may raise blood pressure. These include cough or cold drugs, diet pills, stimulants, ibuprofen or like products, and some natural products or aids.

Talk with your doctor before you drink alcohol.

Watch for gout attacks.

If you have lupus, indapamide can make your lupus active or get worse. Tell your doctor right away if you get any new or worse signs.

Tell your doctor if you have too much sweat, fluid loss, throwing up, or loose stools. This may lead to low blood pressure.

If you are 65 or older, use indapamide with care. You could have more side effects.

Tell your doctor if you are pregnant or plan on getting pregnant. You will need to talk about the benefits and risks of using indapamide while you are pregnant.

Pregnancy level

B

Related drugs

Metolazone , Hydrochlorothiazide , Chlorothiazide , Chlorthalidone , Bendroflumethiazide