Merlactone
Merlactone Uses, Dosage, Side Effects, Food Interaction and all others data.
Merlactone is a specific pharmacologic antagonist of aldosterone, acting primarily through competitive binding of receptors at the aldosterone-dependent sodium-potassium exchange site in the distal convoluted renal tubule. Merlactone causes increased amounts of sodium and water to be excreted, while potassium is retained. Merlactone acts both as a diuretic and as an antihypertensive drug by this mechanism. It may be given alone or with other diuretic agents which act more proximally in the renal tubule. Aldosterone interacts with a cytoplasmic mineralocorticoid receptor to enhance the expression of the Na+ K+ ATPase and the Na+ channel involved in a Na+ K+transport in the distal tubule . Merlactone bind to this mineralcorticoid receptor, blocking the actions of aldosterone on gene expression. Aldosterone is a hormone; its primary function is to retain sodium and excrete potassium in the kidneys.
Originally spironolactone was only studied for its potassium sparing diuretic effect. Merlactone competitively inhibits mineralocorticoid receptors in the distal convoluted tubule to promote sodium and water excretion and potassium retention.. Inhibition of this receptor leads to increased renin and aldosterone levels.
Merlactone is structurally similar to progesterone and as a result is associated with progestogenic and antiandrogenic effects.
| Trade Name | Merlactone |
| Availability | Prescription only |
| Generic | Spironolactone |
| Spironolactone Other Names | Espironolactona, Spironolactone, Spironolactonum, Spironolattone |
| Related Drugs | amlodipine, lisinopril, metoprolol, losartan, furosemide, carvedilol, hydrochlorothiazide, warfarin, Lasix, chlorthalidone |
| Type | |
| Formula | C24H32O4S |
| Weight | Average: 416.573 Monoisotopic: 416.202130202 |
| Protein binding | >90%. Canrenone is as much as 98% protein bound. |
| Groups | Approved |
| Therapeutic Class | Potassium-sparing diuretics, Potassium-sparing diuretics & Aldosterone antagonists |
| Manufacturer | |
| Available Country | Japan |
| Last Updated: | September 19, 2023 at 7:00 am |
Uses
Merlactone is used for Congestive heart failure, Hepatic cirrhosis with ascites and oedema, Nephrotic syndrome, Primary hyperaldosteronism, Essential hypertension, For the treatment of patients with hypokalemia
Merlactone is a long-acting aldosterone antagonist. Merlactone is a specific pharmacologic antagonist of aldosterone, acting primarily through competitive binding of receptors at the aldosterone dependent sodium-potassium exchange site in the distal convoluted renal tubule. Merlactone causes increased amounts of sodium and water to be excreted, while potassium and magnesium is retained.
Merlactone is also used to associated treatment for these conditions: Acne, Ascites, Congestive Heart Failure (CHF), Edema, High Blood Pressure (Hypertension), Hypokalemia, Idiopathic Hirsutism, Nephrotic Syndrome, Primary Hyperaldosteronism, Secondary hyperaldosteronism, Chronic heart failure with reduced ejection fraction (NYHA Class III), Chronic heart failure with reduced ejection fraction (NYHA Class IV), Idiopathic hyperaldosteronism
How Merlactone works
Merlactone competitively inhibits aldosterone dependant sodium potassium exchange channels in the distal convoluted tubule. This action leads to increased sodium and water excretion, but more potassium retention. The increased excretion of water leads to diuretic and also antihypertensive effects.
Dosage
Merlactone dosage
Edema in adults (congestive heart failure, hepatic cirrhosis, or nephrotic syndrome): An initial daily dosage of 100 mg of Merlactone administered in either single or divided doses is recommended, but may range from 25 to 200 mg daily. Combined therapy with other diuretics is indicated when more rapid diuresis is desired.
Primary hyperaldosteronism: After the diagnosis of hyperaldosteronism has been established, Merlactone may be administered in doses of 100 to 400 mg daily in preparation for surgery. For patients who are considered unsuitable for surgery, Merlactone may be employed for long-term maintenance therapy at the lowest effective dosage determined for the individual patient.
Essential hypertension: For adults, an initial daily dosage of 50 to 100 mg of Merlactone administered in either single or divided doses is recommended.
Hypokalemia: Merlactone in a dosage ranging from 25 mg to 100 mg daily is useful in treating a diuretic-induced hypokalemia.
Side Effects
Gynaecomastia may develop in association with the use of Merlactone. Other adverse reactions are: GI symptoms including cramping and diarrhoea, drowsiness, lethargy, headache, urticaria, mental confusion, impotence, irregular menses or amenorrhoea and post-menopausal bleeding.
Toxicity
Patients experiencing an overdose may present with drowsiness, mental confusion, maculopapular or erythematous rash, nausea, vomiting, dizziness, or diarrhea. Vomiting is generally induced or a gastric lavage is performed. Supportive treatment involves maintining hydration, electrolyte balance, and vital functions.
The oral LD50 in mice, rats, and rabbits is >1g/kg.
Merlactone should be avoided in pregnancy due to reports of feminization of male fetuses in animal studies. Active metabolites of spironolactone are present in breast milk and levels that are likely inconsequential, though the long term effects have not been studied.
In animal studies, spironolactone slowed follicle development, ovulation, and implantation. Merlactone increased the incidence of benign adenomas in the testes of male rats, benign uterine endometrial stromal polyps in female rats, and thyroid follicular cell adenomas in both sexes of rats. Merlactone and canrenone are generally not considered to be mutagenic in tests but canrenone occasionally tests positive for mutagenicity with metabolic activation and spironolactone has occasionally tested inconclusive though slightly positive for mutagenicity.
Precaution
All patients receiving diuretic therapy should be observed for evidence of fluid or electrolyte imbalance. Hyperkalemia may occur in patients with impaired renal function or excessive potassium intake and can cause cardiac irregularities, which may be fatal.
Interaction
ACE inhibitors: Concomitant administration of ACE inhibitors with potassium-sparing diuretics has been associated with severe hyperkalemia.
Alcohol, barbiturates, or narcotics: Potentiation of orthostatic hypotension may occur.
Corticosteroids, ACTH: Intensified electrolyte depletion, particularly hypokalemia, may occur.
Lithium: Lithium generally should not be given with diuretics. Diuretic agents reduce the renal clearance of lithium and add a high risk of lithium toxicity.
Digoxin: Merlactone has been shown to increase the half-life of digoxin.
Food Interaction
- Avoid alcohol.
- Avoid potassium-containing products. Potassium products increase the risk of hyperkalemia.
- Take with or without food. Food increases the bioavailability of spironolactone by nearly 100%. It should be taken at a consistent time in regards to food.
Merlactone Alcohol interaction
[Moderate]
Many psychotherapeutic and CNS-active agents (e.g., anxiolytics, sedatives, hypnotics, antidepressants, antipsychotics, opioids, alcohol, muscle relaxants) exhibit hypotensive effects, especially during initiation of therapy and dose escalation.
Coadministration with antihypertensives and other hypotensive agents, in particular vasodilators and alpha-blockers, may result in additive effects on blood pressure and orthostasis.
Caution and close monitoring for development of hypotension is advised during coadministration of these agents.
Some authorities recommend avoiding alcohol in patients receiving vasodilating antihypertensive drugs.
Patients should be advised to avoid rising abruptly from a sitting or recumbent position and to notify their physician if they experience dizziness, lightheadedness, syncope, orthostasis, or tachycardia.
Merlactone Drug Interaction
Major: sacubitril / valsartanModerate: duloxetine, apixaban, metoprolol, metoprolol, alprazolamMinor: aspirin, aspirinUnknown: omega-3 polyunsaturated fatty acids, furosemide, atorvastatin, pregabalin, clopidogrel, montelukast, levothyroxine, acetaminophen, cyanocobalamin, ascorbic acid, cholecalciferol, cetirizine
Merlactone Disease Interaction
Major: acidosis, diabetes, electrolytes/fluid, hyperkalemia, liver disease, renal dysfunctionModerate: hyperuricemia
Volume of Distribution
Volume of distribution data is not readily available.
Elimination Route
Merlactone reaches a maximum concentration in 2.6 hours and an active metabolite (canrenone) reaches a maximum concentration in 4.3 hours. When taken with food, the bioavailability of spironolactone increases to 95.4%.
Giving spironolactone with food increases the maximum concentration from 209ng/mL to 301ng/mL. The time to maximum concentration also increases from 2.28 hours to 3.05 hours. The area under the curve varies from 2103ng/mL*hr to 4544ng/mL*hr.
Half Life
1.4 hours.
Canrenone has a half life of 16.5 hours, 7-α-thiomethylspirolactone has a half life of 13.8 hours, and 6-ß-hydroxy-7-α-thiomethylspirolactone has a half life of 15 hours.
Clearance
Clearance data is not readily available.
Elimination Route
Metabolites of spironolactone are excreted 42-56% in urine, and 14.2-14.6% in the feces. No unmetabolized spironolactone is present in the urine.
Pregnancy & Breastfeeding use
Pregnancy: Merlactone should not be used during pregnancy
Lactation: Canrenone, an active metabolite of Merlactone, appears in breast milk. If use of the drug is deemed essential an alternative method of infant feeding should be instituted.
Contraindication
Merlactone is contraindicated in patients with acute renal insufficiency, significant impairment of renal function, anuria, hyperkalaemia or sensitivity to Merlactone.
Acute Overdose
Symptoms of overdosage include drowsiness, mental confusion, dizziness, diarrhea and vomiting etc. Patients should induce vomiting or evacuate the stomach by lavage during Merlactone overdoasge.
Storage Condition
Store in a cool and dry place protected from light. Keep out of reach of children.
Innovators Monograph
You find simplified version here Merlactone
Merlactone contains Spironolactone see full prescribing information from innovator Merlactone Monograph, Merlactone MSDS, Merlactone FDA label
FAQ
What is Merlactone used for?
Merlactone is used to treat or prevent hypokalemia.It prevents your body from absorbing too much salt and keeps your potassium levels from getting too low.
How safe is Merlactone?
Merlactone is generally considered safe for healthy women. Taking both Merlactone and the pill can increase effectiveness. This combination has another advantage. It's essential to use birth control while taking Merlactone.
How does Merlactone work?
Merlactone works to protect the heart, lower blood pressure, and help with any leg swelling that a weak heart can cause.
What are the common side effects of Merlactone?
Common side effects of Merlactone drowsiness, dizziness, lightheadedness, stomach upset, diarrhea, nausea, vomiting, or headache may occur. To minimize lightheadedness, get up slowly when rising from a seated or lying position. If any of these effects persist or worsen, notify your doctor or pharmacist promptly.
Is Merlactone safe during pregnancy?
Women should not take Merlactone if they are pregnant.Because of the potential risk to the male fetus due to anti-androgenic properties of Merlactone and animal data, avoid Merlactone in pregnant women or advise a pregnant woman of the potential risk to a male fetus.
Is Merlactone safe during breastfeeding?
Merlactone appears acceptable to use during breastfeeding.
Can I drink alcohol with Merlactone?
It is best to limit your intake of alcohol while taking Merlactone. Alcohol can increase the risk for low blood pressure and dizziness. If the blood pressure drops too low, you may feel dizzy or faint, in some cases falls or fainting may occur.
Can I drive after taking Merlactone?
Do not drive or operate machinery if Merlactone makes you drowsy or impairs your judgment. Your doctor may need to periodically monitor electrolyte levels in your blood while you are taking Merlactone.
When is the best time to take Merlactone?
It is best to take your dose early in the day to prevent having to get up during the night to urinate.Take the tablets with or just after a meal.
Should I take Merlactone before or after eating?
You may take this medicine with or without food, but it should be taken the same way (with or without food) each day.
When should not I take Merlactone?
You should not use Merlactone if you Addison's disease, high levels of potassium in your blood, if you are unable to urinate, or if you are also taking eplerenone.
Can you take spironolactone before bed?
You can take Merlactone with or without food, but make sure you pick one way and stick to it. Also avoid taking it before bedtime since it can make you go to the bathroom.
Does Merlactone affect sleep?
Merlactone oral tablet may cause drowsiness.
How long can I stay on Merlactone?
Merlactone usually needs to be continued for up to six months before the benefit can be seen.
Can Merlactone be taken long-term?
long-term use of Merlactone in the treatment of acne in women appears to be safe.
What are the benefits of taking Merlactone?
benefits of taking Merlactone to protect the heart, lower blood pressure, and help with any leg swelling that a weak heart can cause.
What happens if I stop taking Merlactone for hair loss?
Some women will find that if they stop taking the Merlactone, the follicles will shrink once again, and the hair loss may resume. If you are worried about hair loss.
Does Merlactone increase estrogen?
Merlactone showed no significant effects on levels of estrogen,
Who should not take Merlactone?
You should not use Merlactone with caution if you have kidney problems, high levels of potassium in your blood, Addison's disease, if you are unable to urinate, or if you are also taking eplerenone.
What happens if I take too much Merlactone?
If too much Merlactone is taken, the symptoms are similar to Merlactone side effects: sleepiness, dizziness, mental confusion, drug rash, nausea, vomiting, or diarrhea. If a Merlactone overdose is suspected, go to an emergency room.
