Phosphodiesterase inhibitors: Types, Uses, Side Effects

Phosphodiesterase inhibitors

Phosphodiesterase Inhibitors are a class of drugs that inhibit phosphodiesterase (PDE) enzymes. PDEs normally break down phosphate groups and lower cAMP or cGMP into target cells.

PDE inhibitors are classified according to the enzymes for which they act as non-specific inhibitors of PDE5, PDE4 and PDE3.

Inhibitors of PDE3 have positive inotropic, vasodilatory and antiplatelet effects used in acute heart failure and peripheral vascular disease. PDE3 inhibitors are not recommended for long-term use because of their strong cardiostimulatory effect in patients with heart failure.

PDE4 inhibitors allow bronchial dilatation in severe COPD.

PDE5 inhibitors cause pulmonary vasodilation and slackening of the smooth muscle of the penis. They are used in pulmonary arterial hypertension and erectile dysfunction. Nitrates or alpha-blockers are highly contraindicated in patients taking PDE5 inhibitors because of the risk of life-threatening hypotension.

Phosphodiestrerase inhibitors are classified into PDE3 and PDE5 inhibitors

  • PDE3 inhibitors
    • Milrinone
    • Amrinone
    • Cilostazol
  • PDE5 inhibitors
    • Sildenafil
    • Tadalafil
    • Verdinafil
    • Udenafil

Phosphodiesterase Inhibitors Type 3 (PDE3 Inhibitors)


Some key highlights of this Phosphodiestrerase inhibitors class are

  • Milrinone is used for the treatment of congestive heart failure
  • Amrinone is Used in the treatment of congestive heart failure.
  • For the reduction of symptoms of intermittent claudication (pain in the legs that occurs with walking and disappears with rest).

1. Milrinone

It is a vasodilator used as a short-term treatment for treat life-threatening heart failure.  Milrinone belongs to a group of drugs called inotropes, which work by helping the heart pump more blood through the body.


Milrinone is used in the treatment of congestive heart failure.

Side Effects

Common side effects of milrinone include

  • Abnormal heart rhythm, and
  • Headache.
  • Dizziness or fainting.
  • Easy bruising or bleeding.
  • Tremors

Less common and more serious side effects include

  • feeling like you might pass out,
  • chest pain,
  • low potassium
  • bronchospasm (wheezing, chest tightness, trouble breathing)

Consult Your doctor if you have the above side effects.


  • Do not drive or operate heavy machinery until you know how milrinone affects you.
  • Get out of bed slowly to avoid dizziness or fainting.

 2. Amrinone

Amrinone (or inamrinone) is a type 3 pyridine phosphodiesterase inhibitor. Amrinone is a positive inotropic cardiotic with vasodilating properties.


Phosphodiesterase 3 inhibitor activity and how to stimulate the influx of calcium ions into the heart cell. Amrinone is an inhibitor of phosphodiesterase (PDE3), leading to an increase in cAMP and cGMP, resulting in increased calcium input, as caused by beta-agonists, resulting in an increased inotropic effect. The main route of excretion in humans is urine, both by inamrinone and by various metabolites (N-glycolyl, N-acetate, glucuronide and N-glucuronide). The chemical interaction with precipitates occurs with amrinone and dextrose or furosemide. Therefore, the mixture of drugs should be avoided.


It is used in the treatment of

  • congestive heart failure.

Side Effects

Common side effects of amrinone include

  • Upset stomach,
  • Lowered platelet counts, and
  • A sudden drop in blood pressure (hypotension).

3. Cilostazol

Cilostazol is an antiplatelet aggregate and a vasodilator. It works by preventing blood cells, called platelets, from clumping together and preventing the formation of harmful clots. It also dilates the blood vessels in the legs. Cilostazol helps the blood to move more easily and ensures the fluidity of blood in your body. Inhibition of platelet aggregation and vasodilation are important mechanisms of cilostazol, used to treat intermittent claudication in peripheral arterial disease. Cilostazol appears to have less cardiostimulant effects than milrinone.


Cilostazol is used to improve the symptoms of a certain blood flow problem in the legs

  • intermittent claudication
  • Cilostazol can decrease the muscle pain/cramps that occur during exercise/walking.

Side Effects

The most common adverse effects of cilostazol are:

  • abdominal pain,
  • abnormal stoolheadache,
  • diarrhea,
  • nausea,
  • upper respiratory tract infections,
  • fluid retention,
  • abnormal heartbeats.
  • dizziness and
  • runny nose.

Phosphodiesterase Inhibitors Type 5 (PDE5 Inhibitors)


  • These drugs are Used for the treatment of erectile dysfunction
  • They are also used for pulmonary hypertension.

1. Sildenafil

Sildenafil belongs to a group of drugs known as Phosphodiesterase Inhibitors type 5 (Phosphodiesterase 5 inhibitors) and  is used to treat male sexual function problems (impotence or erectile dysfunction-ED). In combination with sexual stimulation, sildenafil works by increasing blood flow to the penis to help a man get and keep an erection.


It is most commonly used for two primary conditions such as

  • Erectile dysfunctions
  • Pulmonary hypertension

Side Effects

The most common side effects include:

  • Nasal congestion
  • Headaches
  • Indigestion
  • Impaired vision
  • Photophobia, or sensitivity to light

Less commonly, some users have experienced cyanopsia, where everything appears to have a tinted blue tinge.

2. Tadalafil

It is in a class of drugs called Phosphodiesterase Inhibitors type-5 (PDE5) inhibitors that also includes sildenafil and vardenafil.


Tadalafil is an oral drug that is used for

  • Treating impotence (the inability to attain or maintain a penile erection) and
  • Benign prostatic hyperplasia (BPH).

Side Effects

The most common side effects of tadalafil are

  • headaches,
  • facial flushing
  • stomach upset,
  • blurred vision,
  • flu-like symptoms, and
  • nausea.
  • diarrhea,
  • abnormal ejaculation.
  • Tadalafil also may cause low blood pressure,
  • changes in color vision

3. Verdenfil

This drug also belongs to a group of drugs known as Phosphodiesterase Inhibitors type -5 (PDE5) inhibitors. Other agents of this group are sildenafil and udenafil. The mechanism of action is same as that of sildenafil.


It is used in the treatment of

  • Erectile dysfunction

Side Effects

Common side effects include

common side effects include:

  • Headache
  • stuffy or runny nose
  • dizziness
  • flushing
  • stomach upset

Vizylac Capsule: Uses, Side Effects, Dose, FAQs

Vizylac Capsule

Vizylac Capsule is a combination of Lactobacillus sporogenes, a healthy intestinal bacteria and a blend of vitamins such as thiamine, riboflavin, pyridoxine, nicotinamide, folic acid and D-panthenol. Ask about the effects of Vizylac, its side effects, precautions and contraindications for which Vizylac is not recommended.

It is a probiotic used to treat diarrhea caused by infections, antibiotics, etc. It is also used to relieve indigestion such as irritable bowel syndrome, inflammatory bowel disease, stomach ulcers, constipation, indigestion, etc.

The Active Ingredients present these Capsule contains D-Panthenol, Folic Acid, Lacto Bacillus Sporegens, Nicotinamide, Pyridoxine, Riboflavin and Thiamine.


Vizylac Capsule is composed of the following active ingredients (salts)
  • Folic Acid – Vitamin B9 – 500 MCG
  • Lacto Bacillus Sporegens – 40 Million Spores
  • Nicotinamide – 22.5 MG
  • Riboflavin – 2.5 MG
  • D-Panthenol – 2.5 MG
  • Thiamine – 2.5 MG
  • Pyridoxine – 0.75 MG

Vizylac Uses

It is used for the treatment, control,  of the following diseases, conditions:
  • Irritable bowel syndrome
  • Acne
  • Diarrhea
  • Skin disorders
  • Diadrrhea
  • Whitish or yellowish discharge of mucus from the vagina
  • Vaginal infection
  • Vitamin b3 deficiency
  • Alzheimer’s disease
  • Whitish or yellowish discharge of mucus from the vagina
  • Treatment of megaloblastic anemias due to a deficiency of folic acid
  • Heart disease
  • Treatment of anemias of nutritional origin, pregnancy, infancy, or childhood
  • Whitish or yellowish discharge of mucus from the vagina
  • Cervical cancer
  • High cholesterol
  • Attention deficit hyperactivity disorder
  • Arthritis
  • Clogged arteries
  • Minor skin injuries
  • Migraine
  • Muscle cramps
  • Cardiovascular diseases
  • Carpal tunnel syndrome
  • Mental disorders
  • Mild burns
  • Sunburns

It may also be used for purposes not listed here.

Mechanism Of Action

  • Vizylac Contains Lactobacillus Sporegens, Vitamin B1, B2, B3, B5, B6 and B9 as its main active ingredient.
  • It is a combination of good bacteria and several vitamins that are deliberately introduced into the intestine to balance the microbial flora (inner environment) of the intestine.
  • The use of antibiotics and other factors can lead to an imbalance between good and bad bacteria and can lead to diseases.
  • The introduction of good bacteria into the body leads to competition between good and bad bacteria for nutrients. By the way to die the bad bacteria by the loss of nutrients Vitamins contained in this drug provide the body with the necessary nutrients.

Vizylac Side effects

The Most common side effects  include

  • Loss of appetite
  • Irritability
  • Head ache
  • Altered Sleep pattern
  • Bloating

while less common side effects

  • Abdominal distension
  • Burning of skin.
  • Ulcer
  • Skin Rashes


  • Vizylac Capsule should be used only if necessary and with caution in cases of pregnancy.
  • It should be used with caution in nursing mothers.
  • It should be avoided in cases of high fever.
  • Dose alteration may be required by the physician in patients with kidney, heart or liver impairments.


Do not take Vizylac Capsule if you are suffering from the following condition:

  • Acute Myocardial Infarction
  • Active Peptic Ulcer
  • Allergic to Panthenol Analogues
  • Diabetes Mellitus
  • Condition of Increased Mast Cells
  • Cardiac Arrhythmias
  • Diabetes Mellitus

Visylac Dosage

  • This is not an over-the-counter medication and a prescription from a qualified physician is required. Follow the instructions of your doctor.
  • General The dose of a Vizylac capsule for an adult is one to two times a day, with an interval of at least 5-6 hours between doses.
  • Consult a pediatrician before giving doses to a child and avoid changing doses without medical advice.

Vizylac Capsule Interactions

It may interact with the following drugs and products:
  • Antibiotic drugs
  • Alcohol
  • Atropine
  • Biotin
  • Barbiturates
  • Carbamazepine
  • Chloramphenicol
  • Chlorthalidone
  • Ciprofloxacin
  • Chlorpromazine

Apart from drugs inerations Vizylac Capsule interact with the following medical conditions and should not used in case of the following condition:

  • Renal Impairment
  • Liver-related disorders
  • Blood Clotting Disorders
  • Renal Impairment
  • Hyperthyroidism
  • Gastrointestinal Blockage
  • Renal Impairment
  • Cardiac Issues
  • High Fever

Frequently Asked Questions (FAQS)

Q. 1 What is Vizylac?

It is a probiotic that contains beneficial bacteria that help improve gastrointestinal problems.

Q. 2 Why is Vizylac Capsule used?

It is a mixture of lactic acid bacillus and various vitamins. It is mainly used to keep the intestines healthy by normalizing the intestinal microflora. It is very useful in the treatment of intestinal infections, indigestion, diarrhea, abdominal conditions, inflammation of the colon, intestine and stomach. It may also be prescribed in some cases of vaginal infections, vitamin B3 deficiency and irritable bowel syndrome.

Q. 3 When is Vizylac Capsule prescribed?

It is a mixture of probiotics and several vitamins. It is mainly used to keep the intestines healthy by normalizing the intestinal microflora. It is prescribed to treat and relieve symptoms associated with intestinal infections, indigestion, diarrhea, abdominal distension, inflammation of the colon, intestines and stomach. Doctors may also prescribe this medication to patients with vaginal infection, vitamin B3 deficiency and irritable bowel syndrome.

Q. 4 What happens if I take an overdose of Vizylac?

Overdose of This can cause unwanted side effects and in some cases lead to complications. Therefore, scrupulously respect the prescribed dose and seek immediate medical attention in case of overdose.

Q. 5 What happens if I miss a dose of Vizylac?

The dose prescribed by the doctor must never be forgotten. If you miss it, you must take it as soon as you remember. However, avoid taking a double dose if the time has already come for the second dose, as this may result in an overdose of the drug.

Q. 6 How to store the Vizylac capsule?

The drug should be stored at room temperature and away from product, direct light and heat. The medication should not be frozen or kept within the reach of children and pets.

Q. 7 What happens if I eat Expired Vizylac?

Expired capsule of this product may have no effects or side effects. However, you must refrain from consuming expired medications.

Q. 8 When to Avoid Vizylac?

you should not takethis In case of known allergy to Vizylac, In patients with gastrointestinal block,  Heart disease: heart disease, disorders of blood clotting,  Hyperthyroidism, Peptic ulcer.

Q. 9 Can I have Vizylac with alcohol?

No, alcohol consumption with Vizylac should be avoided. The doctor must be informed before taking alcohol with Vizylac. Always be consulted.

Q. 10 Is it safe to use during pregnancy?

No, should only be used if necessary during pregnancy and with caution, as this is not without danger. Always tell your doctor before taking this if you are pregnant or intend to become pregnant.

Q. 11 Can I have Vizylac while feeding a baby?

No, Vizylac should not be used in nursing mothers. It should be used only when necessary and should be used with caution.

Q. 12 Should Vizylac be taken on an empty stomach?

Vizylac should not take an empty stomach to avoid stomach upset.

Q. 13 Can I drive after taking Vizylac capsules?

If you feel drowsy or have a headache, you should not drive after consuming the medicine. If you notice any of these symptoms, it is absolutely safe to drive.

Q. 14 Is Vizylac a habit that forms a drug?

The drug does not cause addiction or abuse. However, make sure the package has been checked to make sure it does not contain any addictive substances. Also be careful not to self-administer the medication. Consult your doctor before increasing the dosage.

Q. 15 Is Vizylac an antibiotic or anti diarrhea drug?

It is neither an antibiotic nor a diarrhea. It is a lactic acid-lactic acid bacillus (Lactobacillus sporegens) and several other vitamins (riboflavin, pyridoxine, thiamine, folic acid, D-panthenol, nicotinamide). It can be used to treat diarrhea and irritable bowel syndrome. Yes, diarrhea and irritable bowel syndrome are some of the most commonly reported uses of this medicine. Please do not use these Capsule for the treatment of diarrhea and irritable bowel before consulting your doctor.

Q. 16 Can Vizylac capsules be given to children?

No, the use of this drug is strictly prohibited for children under 3 years of age. For specific recommendations for each case consult a physician.

Q. 17 What other medicines should not be taken with Vizylac Capsule?

It is strongly recommended to avoid any interaction of these Capsule with the following medications: Atropin, Barbiturates, Biotin, Carbamazepine, and other. check above interactions.