Table of Contents
- Organ Transplantation in the United States
- What is Tacrolimus?
- How does Tacrolimus work?
- How to Take Tacrolimus?
- Common Dosage for Tacrolimus
- When to Avoid Tacrolimus?
- Side-effects of Tacrolimus
- Effects on organs
- Reported Allergic Reactions
- Effect of Tacrolimus on the menstrual cycle
- Drug Interactions to Be Careful About
- Food interactions
- Interactions with laboratory procedures
- Shows Effects / Results in (how long does the effect stay?)
- Is Tacrolimus Addictive?
- Can I have Tacrolimus with alcohol?
- Can I have Tacrolimus When Pregnant?
- Can I have Tacrolimus when feeding a baby?
- Can I drive after taking Tacrolimus?
- Effect of an overdose of Tacrolimus
- Effect of using expired Tacrolimus
- Effect of missing a dose of Tacrolimus
- Storage requirements
Organ Transplantation in the United States
Despite an increase in the number of organ transplant surgeries in the United States, there is a progressive need for organs. Approximately 7 lakh organ transplantations have been done in the United States since 1988. The year 2018 witnessed approximately 40,000 organ transplantations in the United States.
What is Tacrolimus?
A basic introduction in brief
Tacrolimus is a macrolide immunosuppressant drug. It was discovered in the year 1987. It is produced by bacterium streptococcus tsukubaensis. It is used after an organ transplant to reduce the risk of organ rejection. It is also used topically in cases of skin conditions such as eczema and psoriasis. It works by interfering with the immune responses of the body.
Type of drug
Tacrolimus is designated as a prescription-only drug. It is to be dispensed by the pharmacist on the presentation of a valid prescription written by a licensed medical practitioner.
Use in brief
Tacrolimus is used for reducing the risk of organ rejection in patients who have undergone a heart transplant, kidney transplant, and liver transplant. The drug is also used in treating psoriasis, eczema, Kimura’s disease, severe refractory uveitis, vitiligo, and exacerbations of minimal change disease.
Tacrolimus is available in various dosage forms.
- Tacrolimus is available in the form of capsules. The available strength of Tacrolimus in capsules is 0.5 mg, 1 mg, and 5 mg of anhydrous Tacrolimus.
- Tacrolimus is also available in the form of granules for suspension intended for oral administration. The unit dose packet contains 0.2 mg and 1 mg of anhydrous tacrolimus.
- Tacrolimus is also available in the form of sterile injection. The injection is available in a volume of 1 ml which contains 5 mg of anhydrous tacrolimus.
Tacrolimus is used in the following indications:
- A prophylactic therapy to prevent organ rejection in patients who had undergone a heart transplant, kidney transplant, bone marrow transplant, and liver transplant.
- To reduce the symptoms of skin conditions such as eczema, vitiligo, and psoriasis.
- In other conditions such as exacerbations of minimal change disease (MCD), Kimura’s disease, and severe refractory uveitis.
How does Tacrolimus work?
Tacrolimus works by inhibiting calcineurin. T-cell receptors are present on T-cells. When an antigen complexed with major histocompatibility complexes (known as antigen-presenting cells) interacts with T-receptors, there is an increase in calcium levels in the cytoplasm. This increase in cytoplasmic calcium levels activates calcineurin via calmodulin. Activated calcineurin then dephosphorylates the transcription factor, also known as the nuclear factor of activated T-cells (NF-AT). These nuclear factors then transported to the nucleus of T-cells where they increase the activity of gene coded for IL-2 and various other cytokines. Tacrolimus prevents the activity of calcineurin by forming a complex of tacrolimus-FKBP-12, calcineurin, calcium, and calmodulin. The inhibition of calcineurin prevents dephosphorylation of the nuclear factor of activated T-cells.
How to Take Tacrolimus?
Form of medicine
Tacrolimus is available as capsules, granules for suspension for oral administration, and injection.
When to use
Tacrolimus is used to prevent organ rejection in cases of organ transplant surgery. The drug is also used to treat various skin disorders.
How to use
Injection of Tacrolimus should only be recommended when the patient is not able to tolerate oral administration. As soon as the patient is fit to take the drug through the oral route, injection is discontinued and oral administration should be started. Tacrolimus injection should only be administered through a continuous infusion. Continuous monitoring of the patients receiving tacrolimus injection is required.
Tacrolimus should be taken with food at the same time each day. Avoid using grape seed extract with tacrolimus as this may interact with tacrolimus. It is contraindicated to use tacrolimus with cyclosporine. Discontinue tacrolimus at least 24 hours before initiating cyclosporine therapy.
Common Dosage for Tacrolimus
The dose of tacrolimus depends upon the type of transplant. In the case of capsules, the tacrolimus dose is initiated 6 after the completion of liver and heart transplant surgery. In kidney transplant patients, tacrolimus capsules are administered within 24 hours of transplantation. However, a delay is allowed until the recovery of renal function. The dose of the tacrolimus capsule in a patient with a kidney transplant is 0.2 mg/kg/day which is divided into two equal doses along with azathioprine. The dose of the tacrolimus capsule in patients with liver transplant is 0.10-0.15 mg/kg/day which is divided into two equal doses along with corticosteroids. The dose of tacrolimus capsules in patients with a heart transplant is 0.075 mg/kg/day which is divided into two equal doses along with Azathioprine or Mycophenolate mofetil.
Starting dose of tacrolimus injection in patients with kidney and liver transplant is 0.03-0.05 mg/kg/day while in heart transplant patients; the starting dose of tacrolimus injection is 0.01 mg/kg/day. The injection should only be given through continuous intravenous infusion. The injection should be discontinued as soon as the patient is in a condition to take the oral form of tacrolimus. The oral form should be given almost 8-12 hours after discontinuation of tacrolimus injection.
In general, the tacrolimus dose is higher in pediatric organ transplant. The dose tends to decrease with age. The dose of tacrolimus in pediatric liver transplant is 0.15-0.2 mg/kg/day capsules or 0.2 mg/kg/day oral suspension which is divided into two equal doses. The dose of tacrolimus in pediatric heart transplant is 0.3 mg/kg/day capsules or oral suspension divided into two equal doses. The dose of tacrolimus in pediatric kidney transplant is 0.3 mg/kg/day capsules or oral suspension divided into two equal doses.
When to Avoid Tacrolimus?
Avoid Tacrolimus injection if you are allergic to Tacrolimus or any of its inactive constituents. You may have mild to severe allergic reactions due to hypersensitivity. Consult with your doctor if you have allergic reactions with any of the dosage form of tacrolimus.
Side-effects of Tacrolimus
Different side effects of tacrolimus are observed in different organ transplantation.
Side effects in kidney transplant:
- Abnormal renal function
- Abdominal pain
Side effects in liver transplant:
Side effects in a heart transplant:
- CMV infection
- Pericardial effusion
Effects on organs
Tacrolimus may also cause side effects in various organs such as:
- Nervous system: Headache, insomnia, dizziness
- Circulatory system: Hypertension, chest pain
- Gastrointestinal system: Diarrhea, abdominal pain, constipation
- Urinary system: Abnormal renal function, urinary tract infection
- Respiratory system: Bronchitis, dyspnea
- Metabolic system: Hyperglycemia, hypermagnesemia, hyperkalemia, hyperlipidemia
- Musculoskeletal: Arthralgia
- Skin: Pruritis, Rashes
Reported Allergic Reactions
Patients who are hypersensitive with tacrolimus of any of the inactive ingredients in tacrolimus formulation may have allergic reactions. Symptoms of an allergic reaction due to tacrolimus include rashes, pruritis, dyspnoea, and acute respiratory distress.
Effect of Tacrolimus on the menstrual cycle
There is no information available regarding the effect of tacrolimus on the menstrual cycle. However, certain patients have reported irregular periods, loss of menstrual cycle, and excessive blood loss. Consult with your healthcare provider in case of a change in the menstrual cycle due to tacrolimus.
Drug Interactions to Be Careful About
Certain medications, when taken along with tacrolimus, may increase or decrease the serum concentration of tacrolimus. Drugs that may interact with tacrolimus are:
Grapefruit or grapefruit juice may increase the concentration of tacrolimus in the serum. Your doctor may inform about possible food interaction with tacrolimus.
Interactions with laboratory procedures
No specific information is available that indicates the interaction of tacrolimus with laboratory tests.
Shows Effects / Results in (how long does the effect stay?)
Tacrolimus has a half-life of 31.9 ± 10.5 hours based on radioactivity, while based on tacrolimus concentration the half-life is 48.4 ± 12.3 hours. Patients with organ transplants have to take tacrolimus throughout their life.
Is Tacrolimus Addictive?
Tacrolimus is non-addictive.
Can I have Tacrolimus with alcohol?
Avoid alcohol while on tacrolimus. Alcohol may increase tacrolimus concentration that may worsen the side effects of tacrolimus.
Can I have Tacrolimus When Pregnant?
Tacrolimus should not be given to pregnant women as it has the potential to harm the fetus. Inform your doctor if you are pregnant or planning to get pregnant.
Can I have Tacrolimus when feeding a baby?
Tacrolimus passes in breast milk. Consult with your healthcare provider before taking tacrolimus if you are breastfeeding.
Can I drive after taking Tacrolimus?
Tacrolimus may cause dizziness, headache, and tremor that may affect your ability to drive. Do not drive until you are perfectly fit to do so.
Effect of an overdose of Tacrolimus
Acute overdosage may result in adverse reactions. Supportive measures are implemented and treatment is initiated according to the symptoms.
Effect of using expired Tacrolimus
Do not take expired tacrolimus. This may result in reduced efficacy or increased side effects of both. Discard expired medications according to the manufacturer’s instruction.
Effect of missing a dose of Tacrolimus
Take tacrolimus as directed and do not miss the dose. In case you have missed the dose, consult with your healthcare provider.
Store tacrolimus capsules and powder for oral suspension at 20°C to 25°C. Tacrolimus injection should be stored at 5°C and 25°C. Keep all medications out of reach of children.
Mr. Rohit Jain is a Pharmaceutical techno-marketing trainer with more than 10 years of industrial experience. In his previous assignment, he was Senior Product Manager, heading the Product Management Team at an organization of repute. Mr. Jain is B. Pharma, MBA, PGDBM, LL.B. and is a Registered Patent Agent. He also has a Professional Diploma in Clinical Research and is also a certified Pharmacovigilance Professional. He was involved in delivering medico-marketing training to on-the-field marketing professionals as well as in-house business development professionals. Mr. Rohit Jain is a prolific medical content writer and had written more than 500 medical articles spreading over varied therapeutic areas. Mr. Jain has a keen interest in learning about the latest happenings of the pharmaceutical and medical industry.