Cyklokapron (tranexamic acid) for hemophilia

Last updated Jan. 24, 2024, by Margarida Maia, PhD
Fact-checked by Inês Martins, PhD

What is Cyklokapron for hemophilia?

Cyklokapron (tranexamic acid) is an approved hemophilia medication that’s designed to control or prevent bleeding episodes in patients, and reduce the need for replacement therapy during and following a tooth extraction. An injectable antifibrinolytic medication — meaning it prevents or slows the breakdown of blood clots — it’s been approved for use in the U.S. for more than 35 years.

It is administered as an intravenous or into-the-vein injection as a short-term treatment given over 2-8 days. The brand-name medication is marketed by Pfizer, but a number of generics are also available in the U.S.

Therapy snapshot

How does Cyklokapron work?

People with hemophilia have a missing or faulty clotting factor, which are the proteins needed for the blood to clot properly, and often experience heavy bleeds that can be difficult to control.

The mainstay treatment for these patients are regular infusions with the missing clotting factor, to ensure patients have enough activity of that protein to help control and prevent bleeds. However, even with these treatments, hemophilia patients are at high risk of experiencing life-threatening bleeding complications when undergoing surgeries, including tooth extractions.

Cyklokapron is an antifibrinolytic medication designed to prevent and control bleeds that may occur during and after a tooth extraction. It works by slowing the break down of blood clots — which are normally degraded too fast in people with hemophilia, particularly in the mouth due to the action of saliva — helping these clots to control bleeding for longer times.

Who can take Cyklokapron?

Cyklokapron was approved by the U.S. Food and Drug Administration in 1986 as a short-term treatment for people with hemophilia. Its use was indicated for two to eight days to control or prevent bleeds and reduce the need for replacement therapy during and following tooth extraction.

Who should not take Cyklokapron?

Cyklokapron is contraindicated, or not recommended, for people with:

• bleeding in the space between the brain and the surrounding membrane, called subarachnoid hemorrhage, due to the risk of brain swelling and lack of blood supply to the brain
• active intravascular clotting, or activation of the blood clotting pathway outside regions of damage
• a severe hypersensitivity, or allergy, to the medication or any of its ingredients.

How is Cyklokapron administered?

Cyklokapron is available as single-dose ampules or vials containing 10 mL of a clear, colorless solution that must be injected slowly, at no more than 1 mL per minute, to avoid causing low blood pressure.

The injectable solution contains 1,000 mg of tranexamic acid, Cyklokapron’s active ingredient, at a concentration of 100 mg/mL.

The medication’s recommended dose is 10 mg per kilogram of body weight, given as a single dose immediately before tooth extractions. The 10 mg/kg injections can then be repeated after the extraction, and given three to four times a day for 2-8 days.

For patients with moderate to severe kidney problems, however, Cyklokapron injections should be given less frequently or at lower doses, depending on the degree of kidney impairment:

• If blood creatinine, a waste metabolite that is increased in people with kidney dysfunction, falls between 1.36 to 2.83 mg per deciliter (dL), patients should receive a 10 mg/kg dose twice daily rather than 3-4 times a day.
• If a patient’s blood creatinine is between 2.83 to 5.66 mg/dL, Cyklokapron should be given at a 10 mg/kg dose daily
• If blood creatinine is higher than 5.66 mg/dL, patients should receive either a 10 mg/kg dose every other day, or a 5 mg/kg dose once daily.

For intravenous infusion, Cyklokapron’s solution may be mixed with most solutions for infusion. Heparin, a blood thinner used to prevent blood clots, also may be added. Cyklokapron contains tranexamic acid, a synthetic amino acid (the building blocks of proteins), and should not be mixed with solutions containing penicillin, an antibiotic.

Importantly, the medication is only designed for intravenous use. Mistakenly injecting Cyklokapron intrathecally, or into the spinal canal, can lead to serious side effects, including seizures and irregular heartbeats. Syringes containing Cyklokapron should be clearly labeled for intravenous use to avoid confusion with other injectable solutions that might be administered at the same time.

Cyklokapron in clinical trials

A small clinical trial conducted in the 70s assessed the safety and efficacy of Cyklokapron in 28 adults and adolescents with hemophilia, ages 13 to 65. Altogether, these patients underwent a total of 32 tooth extraction procedures. Eight patients had hemophilia B and 20 had hemophilia A.

The participants were randomly assigned to receive either 1 gram of oral Cyklokapron three times a day, or a placebo, two hours before tooth extraction and for five days following the procedure. All were also treated with standard replacement therapy one hour before the procedure and then at their clinician’s discretion.

The results showed that the mean volume of blood lost was significantly less for patients on Cyklokapron than for those on a placebo (61.2 vs. 84.1 mL). Also, fewer of these patients required replacement therapy following tooth extraction (14.3% vs. 78.6%). No side effects were reported.

After this trial, a number of other studies have demonstrated Cyklokapron’s safety and efficacy at controlling and preventing bleeds in people with hemophilia undergoing tooth extractions or other oral procedures, while also reducing the need for replacement therapy use.

Common side effects of Cyklokapron

The most common side effects that have been reported with the use of Cyklokapron include:

• nausea
• vomiting
• diarrhea
• allergic dermatitis, or an allergic reaction affecting the skin
• dizziness
• low blood pressure, known as hypotension
• thromboembolic events, which occur when a blood clot that forms in a blood vessel breaks loose, travels in the bloodstream, and becomes lodged in another blood vessel, blocking blood flow.

Blood clotting problems

Cyklokapron can increase the risk of thromboembolic events, and its use with pro-thrombotic medications — treatments that may cause blood clots to form — should be avoided. These medications include factor IX complex concentrates, anti-inhibitor coagulant concentrates such as FEIBA, and hormonal contraceptives.

Seizures

Use of the medication may cause seizures, which mainly have been reported in patients who received Cyklokapron during cardiovascular surgery at doses up to 10 times higher than the recommended dose. Seizures also may occur if the therapy is inadvertently administered into the spinal canal.

For patients with a history of seizures, or sudden twitches or jerks known as myoclonic movements, an electroencephalogram (EEG) may be considered to monitor the brain’s electrical activity during surgery. If seizures happen, treatment with Cyklokapron should be stopped.

Allergic reactions

Cyklokapron or its ingredients may cause allergic reactions, including a severe reaction called anaphylaxis. If symptoms of a severe reaction develop, treatment with Cyklokapron should be stopped and not restarted, and urgent medical attention should be sought.

Vision problems

In cats and dogs, at doses higher than recommended for humans, studies have shown that Cyklokapron can cause damage to the retina, the light-sensitive layer at the back of the eye.

Retinal changes have not been reported in patients to date, but it’s recommended that those undergoing treatment for more than three months receive regular eye exams to monitor changes to their vision. If vision problems develop, treatment with Cyklokapron should be discontinued.

Dizziness

Cyklokapron may cause dizziness, which can be exacerbated with the use of other medications.  Thus, it’s recommended that patients starting treatment avoid driving or using machines until they know how Cyklokapron affects them.

Use in pregnancy and breastfeeding

Preclinical studies in animals have not revealed any harmful effects to a developing fetus when Cyklokapron was administered during pregnancy. However, it’s not known if the medication can increase the risk of miscarriage, or impact fetal outcomes. The medication has been found in human milk, but it’s also not known if it has an effect on milk production or on a breastfed child.

Thus, women who are pregnant or planning to become pregnant, and those who are nursing or planning to breastfeed, should carefully weight the potential benefits of using Cyklokapron in these circumstances against its potential risks.

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