Diflucan Uses, Dosage, Side Effects, Food Interaction and all others data.

Diflucan is fungistatic in action. It inhibits cytochrome P-450 14-α demethylase in susceptible fungi which leads to accumulation of lanosterol and decreased concentration of ergosterol thereby altering cellular membrane resulting in increased membrane permeability, leakage of essential elements and impaired uptake of precursor molecules to DNA.

Diflucan has been demonstrated to show fungistatic activity against the majority of strains of the following microorganisms, curing fungal infections:

Candida albicans, Candida glabrata (Many strains are intermediately susceptible), Candida parapsilosis, Candida tropicalis, Cryptococcus neoformans

This is achieved through steroidal inhibition in fungal cells, interfering with cell wall synthesis and growth as well as cell adhesion, thereby treating fungal infections and their symptoms.

Trade Name Diflucan
Availability Prescription only
Generic Fluconazole
Fluconazole Other Names Diflucan, Difluconazole, Fluconazol, Fluconazole, Fluconazolum, Triflucan
Related Drugs nystatin, nystatin topical, clotrimazole topical, clotrimazole, ketoconazole, Diflucan, itraconazole, miconazole topical, miconazole, cisplatin
Weight 150mg, 200mg, 50mg, 2mg/ml, 50mg/5ml, , 200mg/100ml + 0.9%, 400mg/200ml + 0.9%, 10mg/ml, 40mg/ml, 100mg
Type Capsule, Infusion, Suspension, Intravenous, Intravenous Solution, Oral Powder For Reconstitution, Oral Tablet, Injection
Formula C13H12F2N6O
Weight Average: 306.2708
Monoisotopic: 306.104065446
Protein binding

The protein binding of fluconazole is low and estimated to be 11 to 12%.

Groups Approved, Investigational
Therapeutic Class Ophthalmic Anti-fungal Products
Manufacturer Pfizer Ltd, Pfizer Laboratories Ltd, , Pfizer Australia Pty Ltd, Pfizer Limited, Pfizer Holding France, Fareva Romainville, Pfizer Indonesia
Available Country India, Pakistan, Philippines, United Kingdom, Canada, Australia, Saudi Arabia, United States, Indonesia, Netherlands, Portugal, Switzerland,
Last Updated: September 19, 2023 at 7:00 am

How Diflucan works

Diflucan is a very selective inhibitor of fungal cytochrome P450 dependent enzyme lanosterol 14-α-demethylase. This enzyme normally works to convert lanosterol to ergosterol, which is necessary for fungal cell wall synthesis. The free nitrogen atom located on the azole ring of fluconazole binds with a single iron atom located in the heme group of lanosterol 14-α-demethylase. This prevents oxygen activation and, as a result, inhibits the demethylation of lanosterol, halting the process of ergosterol biosynthesis. Methylated sterols are then found to accumulate in the fungal cellular membrane, leading to an arrest of fungal growth. These accumulated sterols negatively affect the structure and function of the fungal cell plasma membrane.

Diflucan resistance may arise from an alteration in the amount or function of the target enzyme (lanosterol 14-α-demethylase), altered access to this enzyme, or a combination of the above. Other mechanisms may also be implicated, and studies are ongoing.


Diflucan dosage

Instill 1 drop to be instilled into the affected eye(s) 5 times daily.

Side Effects

This drug is generally well tolerated. Eosinophillia has been reported in some patients.


Acute oral toxicity (LD50): 1271 mg/kg (rat)

Overdose information

Diflucan overdoses have been associated with hallucination and paranoia, sometimes in combination. In cases of overdose, employ supportive treatment. Gastric lavage may be necessary. Other modalities such as forced diuresis or hemodialysis may also be used.

A note on liver toxicity

The FDA label warns that this drug carries a risk of hepatotoxicity. Rare but serious cases of serious hepatic toxicity have been reported, especially in patients with serious underlying medical conditions using fluconazole. This group of patients has an increased risk of fatality when using fluconazole. In patients with existing liver dysfunction, use caution during fluconazole therapy. Those who are found to have abnormal liver function tests during therapy should be carefully monitored for the development of increasingly severe injury to the liver. Diflucan should be stopped if its use is likely to be the underlying cause of liver injury, and medical attention should be sought. Diflucan induced hepatotoxicity is usually reversible.

Carcinogenesis, mutagenesis, and impairment of fertility

Diflucan demonstrated no evidence of carcinogenic risk in mice and rats treated orally for 24 months at doses equivalent to approximately 2-7 time the recommended human dose). Male rats given fluconazole at doses equivalent to supratherapeutic human doses showed an increased incidence of hepatocellular adenomas. Cytogenetic studies in vivo and in vitro demonstrated no sign of chromosomal mutation. The significance of these findings for humans is unknown.

Use in pregnancy

There are no sufficient and well-controlled studies of fluconazole use in pregnant women. Available human data do not show an increased risk of congenital anomalies after pregnant women were treated with standard doses (27 Several case reports describe rare but striking congenital anomalies observed in infants who were exposed to fluconazole at high doses reaching 400-800 mg/day, primarily in the first trimester of pregnancy. Similar findings were observed in animal studies. If this drug is administered during pregnancy, or if the patient becomes pregnant while taking fluconazole, the risk should be discussed thoroughly.

Use in nursing

Diflucan is secreted in breastmilk at high concentrations. Exercise caution if this drug is used during nursing.


Use of fluconazole may result in overgrowth of non-susceptible strains of candida other than Candida albicans


Diflucan can alter pharmacokinetics of certain drugs undergoing hepatic metabolism.

Food Interaction

  • Take with or without food. The absorption is unaffected by food.

Volume of Distribution

The apparent volume of distribution is said to be similar to the volume of distribution of total body water. One clinical study of healthy volunteers administered 50 mg/kg of fluconazole was 39L, based on a body weight of 60kg.

Diflucan shows substantial penetration in many body fluids, which is a property that renders it an ideal treatment for systemic fungal infections, especially when administered over a longer time. Diflucan is found in high concentrations in the stratum corneum and dermis-epidermis of skin, in addition to eccrine sweat. Diflucan is found to accumulate especially well in the stratum corneum, which is beneficial in superficial fungal infections.[L6496] Saliva and sputum concentrations of fluconazole are found to be similar to the plasma concentrations. In patients diagnosed with fungal meningitis, fluconazole CSF (cerebrospinal fluid) levels are measured to be about 80% of the corresponding plasma levels. Therefore, fluconazole crosses the blood-brain barrier[L6496]. The meninges are increasingly permeable to fluconazole in states of inflammation, facilitating treatment in meningitis.

Elimination Route

The pharmacokinetic properties of fluconazole are comparable after administration by the intravenous (IV) and oral (PO) routes. In healthy volunteers, the bioavailability of orally administered fluconazole is measured to be above 90%. It is extensively absorbed in the gastrointestinal tract when an oral dose is taken. Oral absorption is not affected by food intake with fluconazole but may increase the time until the maximum concentration is reached.

Tmax (or the time taken to achieve the maximum concentration) in one clinical study of healthy patients receiving 50 mg/kg of fluconazole was 3 hours.

Peak plasma concentrations (Cmax) in fasting and healthy volunteers occur between 1-2 hours post-dose. Steady-state concentrations are achieved within 5 to 10 days after oral doses of 50-400 mg administered once daily. Administration of a loading dose on the first day of fluconazole treatment, or twice the usual daily dose, leads to plasma concentrations close to steady-state by the second day. Mean AUC (area under the curve) was 20.3 in healthy volunteers receiving 25 mg of fluconazole.

A note on the capsule and powder form and malabsorption syndromes

The capsule forms of fluconazole often contain lactose and should not be administered with hereditary galactose intolerance, Lapp lactase enzyme deficiency, or malabsorption of glucose/galactose. The powder form, used for the oral suspension, lists sucrose as an ingredient and should not be used in patients who have been diagnosed with fructose, glucose/galactose malabsorption, and sucrase-isomaltase enzyme deficiency.

Half Life

The terminal elimination half-life in the plasma is approximately 30 hours (range: 20-50 hours) after oral administration. The long plasma elimination half-life supports a single dose therapy for vaginal candidiasis, once daily and once weekly dosing for other indications.[L6496]. Patients with renal failure may require dosage adjustment, and half-life can be significantly increased in these patients.


This drug is mainly eliminated by the kidneys and the mean body clearance in adults is reported to be 0.23 mL/min/kg. One clinical study of healthy subjects showed total clearance of 19.5 ± 4.7 mL/min and renal clearance of 14.7 ± 3.7 mL/min (1.17 ± 0.28 and 0.88 ± 0.22 L/h).

Clearance in the pediatric population varies according to age, as does clearance in patients with renal failure.

Elimination Route

In normal volunteers, fluconazole is cleared primarily by renal excretion, with approximately 80% of the administered dose measured in the urine as unchanged drug. About 11% of the dose is excreted in the urine as metabolites.. A study of a 50mg radiolabeled dose of fluconazole revealed that 93.3% of the dose was found excreted in the urine.

A note on renal failure

The pharmacokinetics of fluconazole are significantly affected by renal dysfunction. The dose of fluconazole may need to be reduced in patients with decreased renal function. A 3-hour hemodialysis treatment lowers plasma fluconazole concentrations by about 50%.

Pregnancy & Breastfeeding use

Use in pregnancy: Pregnancy category C. There are no adequate and well-controlled studies in pregnant women. Diflucan should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Use in lactation: Nursing mother should not be given as the drug is excreted in breast milk in concentration similar to plasma.


The drug is contraindicated in patients with hypersensitivity to azoles.

Storage Condition

Keep out of the reach of children. Store in a cool, dry place, away from heat and direct light. Do not use more than 4 weeks after opening the bottle

Innovators Monograph

You find simplified version here Diflucan


What does Diflucan used for?

Diflucan is used to prevent and treat a variety of fungal and yeast infections like mucocutaneous candidiasis, including esophageal candidiasis (infection of the esophagus), oropharyngeal candidiasis (infection of part of the throat), cryptococcal meningitis and vulvovaginal candidiasis (infection of the vulva and vagina). It belongs to a class of drugs called azole antifungals. It works by stopping the growth of certain types of fungus. Treat to Prevent candidiasis in people undergoing bone marrow transplantation who are receiving chemotherapy and/or radiation. 

How quickly does Diflucan work?

Diflucan begins resolving symptoms in 4 hours, with complete resolution in as soon as 16 hours for uncomplicated cases. More complex cases or repeated infections may require longer treatment durations to achieve complete resolution.

Is Diflucan an antibiotic?

Diflucan belongs to a group of medicines called azole antibiotics. It works by preventing the growth of the fungal and yeast organisms causing your infection.

What should I avoid while taking Diflucan?

Common medications that may interact with Diflucan include: anticoagulants or antiplatelet agents (blood thinners), such as warfarin, clopidogrel, (may prolong bleeding time) biologics, such as acalabrutinib, bosutinib, or entrectinib. albuterol.

How long does a yeast infection last after taking Diflucan?

Diflucan is used for many different fungal infections. If you have vaginal thrush, balanitis or oral thrush, your symptoms should be better within 7 days of taking Diflucan.

Can I take two doses of Diflucan?

Single-dose Diflucan is highly effective in complicated Candida vaginal infections, the clinical cure rate is better when a second sequential dose is used.

How do I know when yeast infection is clearing up?

  • First, you will notice that vaginal discharge has returned to a normal consistency and smell.
  • Second, you will notice that itching has gone away, alleviating much of the discomfort associated with the infection.
  • Third, you will notice that any rash, swelling, or redness has subsided. Your genitals should return to a healthy appearance and feel.

How Long Does a Yeast Infection Last?

If a mild yeast infection is left untreated, it may go away on its own in a few days. More severe yeast infections could take up to 2 weeks to clear without treatment. If your infection is causing painful and uncomfortable symptoms for more than 3 days, you should seek medical treatment.

What Is a Yeast Infection?

A yeast infection, also known as candida vulvovaginitis, is a common infection that 3 out of 4 women will experience throughout their lives. Yeast infections are not considered sexually transmitted infections (STIs). Every woman’s vagina has a delicate balance of live bacteria and yeast cells. When this balance is thrown off, yeast cells can multiply, which may result in a yeast infection.

How do I know if I have a yeast infection?

The most common symptoms of vaginal yeast infection include:

  • Stinging sensations in the vagina or vulva
  • Persistent itchiness in the genital area
  • Pain during intercourse
  • Pain during urination
  • Stinging sensations in the vagina or vulva
  • Pain during intercourse
  • What does a yeast infection look like?
  • Thick, lumpy vaginal discharge
  • Redness in the vagina and vulva
  • Swelling of the labia and vulva
  • smell like Strong, musty odor, Fishy, sour odor or abnormal smell

How long does it take to recover from Yeast infection?

Without treatment, it takes 3–7 days to recover from a yeast infection. It can take 1–2 weeks to recover from a moderate to severe yeast infection.

What happens if I stop taking Diflucan?

Do not stop taking Diflucan without talking to your doctor. If you stop taking Diflucan too soon, your infection may come back after a short time.

What are the side effects of Diflucan?

Diflucan Side Effects are

  • Chills.
  • general feeling of tiredness or weakness.
  • hives, itching, or skin rash.
  • large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or genitals.
  • light-colored stools.
  • stomach pain, continuing.
  • upper right abdominal or stomach pain.
  • yellow eyes and skin.

What infections does Diflucan treat?

Diflucan is used to treat serious fungal or yeast infections, such as vaginal candidiasis, oropharyngeal candidiasis (thrush, oral thrush), esophageal candidiasis (candida esophagitis), other candida infections (including urinary tract infections, peritonitis [inflammation of the lining of abdomen or stomach], and infections that may occur in different parts of the body), or fungal (cryptococcal) meningitis. This medicine works by killing the fungus or yeast, or preventing its growth.

Diflucan is also used to prevent candidiasis in patients having bone marrow transplants who receive cancer or radiation treatment.

What is the best time of day to take Diflucan?

Diflucan can be taken at any time of day, and can be taken either before or after a meal. Swallow the capsule with a drink of water. Infections such as vaginal thrush can be treated with a single 150 mg dose; other infections require a course of treatment possibly lasting a number of weeks.

Can I drink milk while taking Diflucan?

Any condition that makes it hard for you to digest sugars or dairy products so take with caution. The capsule form of Diflucan contains lactose (milk sugar) and the oral liquid contains sucrose (table sugar), which can make these conditions worse.

How much Diflucan should I take for a yeast infection?

The treatment of choice is a single 150 mg oral fluconazole (Diflucan). Most women consider the pill more convenient than creams applied intravaginally. A cool fact is that a single 150 mg dose of Diflucan maintains therapeutic concentrations in vaginal secretions for at least 72 hours after you take it.

Can men take Diflucan?

Men with severe yeast infections or those involving the penis may need to take an antifungal in pill form, like fluconazole (Diflucan), which is available by prescription from your doctor.

Can sperm cause yeast infections?

But sometimes sexual activity can lead to vaginitis. Your partner's natural genital chemistry can change the balance of yeast and bacteria in your vagina. In rare cases, you can have an allergic reaction to your partner's semen.

Why do I keep getting yeast infections from my boyfriend?

Intercourse introduces bacteria from your partner's finger or penis into your vagina's ecosystem of bacteria and Candida. Sex toys can also transmit it. This disruption may be enough to trigger a vaginal yeast infection.

Is it bad to scratch when I have a yeast infection?

Even though yeast infections can be really itchy, try not to scratch. It can make irritation worse or cause cuts in your skin, which can spread germs and lead to more infection. There are over-the-counter creams that you can use on your vulva to help calm the irritation.

Which is better clotrimazole or (Diflucan) fluconazole?

Fluconazole (Diflucan) can more successfully and safely cure clinical and micrological symptom of VVC than clotrimazole and can be more effective in reduction of the relapse rate of the disease than clotrimazole.

*** Taking medicines without doctor's advice can cause long-term problems.