To avoid severe side effects of Heparin, it’s advisable to adhere to Heparin dosage which is determined by:
- The age of the patient
- The condition being treated
- How serious the condition is
- Existing medical conditions
- How one reacts to the initial dose
- The weight of the patient
What is Heparin?
It is a prescription medication either injected under the skin or into the vein. It belongs to a family of drugs known as anticoagulants. It is a blood thinner administered to treat and prevent blood clots in the arteries, veins, and lungs. The drug is available in the following forms:
- Standard (unfractionated) Heparin
- Low molecular weight Heparin (LMWH)
Standard Heparin is given:
- Through the veins (an intravenous injection)
- Intravenous infusion – a continuous drip of the medication is fed via a narrow tube and into a vein in the arm (this is carried out in the hospital)
- An injection under the skin (subcutaneously)
On the other hand, low molecular weight Heparin is given as a shot under the skin. The person taking this particular dose of Heparin is monitored and its adjusted if need be. An individual may be hospitalized for five to ten days and blood test may be done to confirm one is on safe dose. LMWH works in a different way since it has small molecules, so its effects are more predictable and reliable thus, there is no need to stay in the hospital.
Normally, after an injury, bleeding occurs, the body reacts by forming a blood clot on the injured spot. After some time, the clot breaks down as your wound heals. However, a person may experience abnormal clotting due to an imbalance between the clot forming and clot breaking down. The drug is used to prevent abnormal clots from forming as well as preventing the existing ones from becoming bigger by stopping the release of particular proteins needed for blood clotting. The medication doesn’t break up or dissolve existing clots. The dosage of this medicine is individualized; it ranges from one person to another, the medication comes in different strength and serious complication can occur if a patient takes an overdose of the drug. Before getting to know what happens after taking an overdose, let’s learn its uses and the exact dose.
As the physician prescribes Heparin, he or she will put into consideration the factors mentioned at the start of the article. A patient is started on the lowest effective dose because a high dose of this medication may lead to bleeding episodes. The medication is used to deal with the following:
- Treating deep vein thrombosis (DVT): it’s a blood clot that develops deep in the vein especially in the leg. Such clots are also termed as venous thrombosis. DVT triggers pain and can result in severe complications like pulmonary embolism, if given in time it can prevent such complications but one should take the right amount of medication as advised; avoid overdose or an underdose. The loading drug dose 5,000 units given into the veins; the maintenance dose is 20,000 to 40,000 units via continuous intravenous infusion per 24 hours. If the dosage is injected under the skin, the initial dose is 333units/kg of body weight, as for the maintenance dose, its 250units/kg of body weight; the shot is given every 12 hours.
- Treating and preventing pulmonary embolism: it is a fatal condition that happens when a clot breaks off into the blood and blocks any of the blood vessels in the lungs. The loading dose 5,000 or 10,000 units if the condition is severe given into the vein; the maintenance dose is 20,000 to 40,000 units via continuous intravenous infusion per 24 hours. If the dosage is injected under the skin, the initial dose is 333units/kg of body weight. As for the maintenance dose, its 250units/kg of body weight; the shot is given every 12 hours.
- Preventing further formation of blood clots immediately after a heart attack – your heart is surrounded by three coronary arteries, whose main role is to supply blood and oxygen to the heart. If a blood clot forms in any of the artery, blood supply to that area is stopped; this is what is referred to as a heart attack or coronary thrombosis or myocardial infarction in medical language. Thus, the drug is given to deal with the blockage (thrombosis), the initial dose being 5,000 units into the veins and the maintenance Heparin dosage is 1,000 to 2,000 units via intravenous infusion or 5,000 to 10,000 units given four hourly through intravenous injection. If need be, to get the desired results, Heparin dose adjustment will be done.
- Preventing a patient blood from clotting during filtration in a machine when heart-lung bypass surgery is being done. A person’s heart beats constantly, heart surgery is a complicated procedure; the heart can’t be stopped for a couple of minutes without leading to brain damage. Thanks to the heart-lung machine also known as cardiopulmonary bypass machine. The machine takes over the role of the heart (it pumps blood and adds oxygen to the blood). During surgery, a specialist operates the machine and monitors the flow of the blood to confirm the heart-lung machine is working properly. Before a patient is hooked to the machine, a low dose of Heparin (but it must be effective) is given to prevent the blood from clotting while in the machine. The loading dose is 300 units/kg of body weight is given intravenously, which may be adjusted after that to keep the ACT (activated clotting time) between the range of 400 to 500 seconds.
- Used during hemodialysis (the process of purifying the blood of an individual whose kidneys are not working as expected) and haemofiltration (renal replacement therapy). The loading dose is 1,000 to 5,000 units. The maintenance dose is 1,000 to 2,000 units per hour and can be adjusted to sustain clotting time (greater than forty minutes)
It’s important to note that the drug dosage of a child is determined by the physician depending on the child’s condition as well as medical history; a child refers to a human from 0 to 17 years. As for the seniors (aged above 60 years of age), Heparin is started on a low dose since they are at risk of bleeding. Patients who are resistance to the drug may require the maximum dose of this medication to get the desired effects.
Treatment of Overdose
One of the possible side effects of this medication is bleeding, that’s why it’s advisable to follow the dosage as directed to avoid taking an overdose. Also, a patient is said to have taken an overdose of Heparin if the ability to form blood clot is impaired; the quantity of the medicine that is toxic is individualized and the bleeding time is based on the level of toxicity. In one take too much of the medication, a patient will experience Heparin overdose symptoms such as:
- Unexpected bleeding, like unusual bleeding from the gums, nose bleeding frequently, and periods that are heavier than normal,
- Blood in the urine
- Dark, tarry stools (may be a sign of internal stomach bleeding)
- Easy bruising and bleeding
- Vomiting blood or which resembles coffee grounds
Once a patient detects the above-listed signs of the drug overdose, it’s crucial to visit a hospital to seek treatment, if medical attention is not given, the situation may be life threatening. What is the treatment of Heparin overdose? The medical care provider will give protamine sulfate through slow infusion. The amount of administered will depend on the excess Heparin taken. Normally, 100 units are neutralized by 1mg of protamine sulfate, however, the maximum amount given is 50 mg within a period of 10 minute and the amount needed reduces with time as Heparin is metabolized.
Continuous treatment of overdose can lead to severe hypotensive (low blood pressure) as well as anaphylactoid reactions which may be sudden, fatal allergic reactions. The symptoms may begin after 15 minutes, your heart beats faster, and blood pressure may fall resulting to fainting. Other signs may include:
- Runny nose
- Breathing difficulty
As the anaphylactic reactions progress a person may stop breathing and lose consciousness. Therefore, the antidote for the drug overdose using protamine should be given only if a standby anaphylactic treatment as well resuscitation equipment is available.
To curb Heparin overdose, take the drug as instructed. Before using it, double check to confirm it’s the right dose as prescribed. Any signs and symptoms of overdose should be reported to the doctor and addressed immediately.