Anticoagulants NCLEX Nursing Pharmacology Review
Nursing Pharmacology Guide on Anticoagulants
Anticoagulants are a group of drugs that are used to prevent blood clot formation. Blood clots are clumps of blood products that can form in the blood vessels. These clots can dislodge and travel into the circulation and get stuck in arteries and veins causing serious medical emergencies such as stroke, heart attack, and pulmonary embolism.
Anticoagulants are widely known as blood thinners. However, contrary to this belief, anticoagulants do not make the blood any thinner. They prevent clots from forming through different mechanisms.
Nursing Stat Facts 1
There are mainly four different types of anticoagulants. Each of the classifications prevents specific chemicals required for clot formation.
Anticoagulants are commonly confused with antiplatelets. These drugs are completely different from each other. Antiplatelets also prevent clot formation, however, their mechanism of action is focused on preventing the abilities of platelets from forming clots.
Indications for Anticoagulants
Anticoagulants are used mainly to prevent blood clot formation such as for those at higher risk of clots due to other medical conditions.
Also, anticoagulants are used to treat existing blood clots and prevent them from getting bigger. The following are common medical conditions that may require anticoagulation therapy:
- Atrial fibrillation – This is one of the most common reasons for anticoagulant use.
- Having a mechanical heart valve
- Mitral stenosis
- Blood disorders such as inherited thrombophilia and antiphospholipid syndrome
- Post hip or knee surgery
- Deep vein thrombosis (DVT)
- Heart attack
- Pulmonary embolism
- Blood clots in arterial or venous catheters
- Stent thrombosis
Actions of Anticoagulants
Following tissue damage, the body reacts by activating platelets by making them sticky and forming them around the damaged area. The activated platelets then signal the proteins in the blood known as clotting factors to convert fibrinogen into strands of strong protein called fibrin.
This will then trap the blood products and form a clot to patch the damaged tissue. This mechanism does not normally cause any problems.
However, when this occurs in the blood vessel, the clot can dislodge and partially or completely block the artery or vein.
Anticoagulants work in different ways depending on the classification.
- Vitamin K Antagonists – These drugs prevent the formation of clotting factors by depleting active vitamin K molecules.
- Low Molecular Weight Heparin – LMWH drugs prevent clot formation by preventing the actions of two of the clotting factors – Factor X and II.
- Direct Thrombin Inhibitors – These drugs prevent the action of thrombin (factor II) from converting fibrinogen into fibrin.
- Factor Xa Inhibitors – These drugs are a newer classification of anticoagulants. They block the action of the clotting factor Xa which then prevents blood clot formation.
Side Effects and Adverse Effects of Anticoagulants
The common side effects of anticoagulants are:
- Bleeding – everyone who takes anticoagulants is at risk of bleeding. It is the most common side effect known to anticoagulants.
- Abdominal pain
- Ecchymosis or easy bruising
- Hair loss
- Itching or pruritus
- Changes in the sense of taste
- Fainting episodes
- Shortness of breath
- Chest pain
More serious side effects associated with anticoagulant therapy may include:
- Cholesterol embolus syndrome
- Intraocular hemorrhage
- Groin hemorrhage
- Tissue necrosis
- Respiratory tract bleeding
- Hypersensitivity reaction
- Hemorrhagic stroke
- Purple toe syndrome
- Increased risk for fractures
- Elevated aminotransferase level
Contraindications and Cautions against Anticoagulants
There are different considerations and cautions related to the intake of anticoagulants. They are commonly discussed by the prescriber before the medication is prescribed.
- A visit to the emergency department is advised following a head injury despite having no symptoms. A head CT will need to be performed to assure the absence of bleeding.
- It is advised to declare the use of anticoagulants if a surgical procedure is planned. This includes dental and orthodontic procedures.
- It is advised to take great caution when engaging in contact activities to prevent bleeding and bruising.
- It is advised to use a soft-bristled toothbrush and an electric razor.
More so, anticoagulant use may be completely contraindicated for use in the following conditions:
- Stomach ulceration
- Hemorrhagic stroke
- Currently taking medicines with undesirable interaction with anticoagulants
- Undergoing surgery
- Very high blood pressure
- Some anticoagulants may be contraindicated with severe kidney disease
- Hemophilia or any other bleeding disorder
- Cerebral aneurysm
- Dissecting aorta
- Pericardial effusion
- Bacterial endocarditis
- An active bleed
Drug Interactions with Anticoagulants
Anticoagulants when taken with other drugs and herbal medicines can cause an increased risk for bleeding.
- Antiplatelets – can increase bleeding risk
- Serotonin Reuptake Inhibitors (SSRIs) – can increase bleeding risk
- Garlic and ginkgo – can increase bleeding risk
Other drugs are known to increase the potency of anticoagulants by reducing their breakdown. These drugs include the following:
- Some antibiotics and antifungals
- Some statins
- Protease inhibitors
On the other hand, some medications can reduce the effectiveness of anticoagulants by increasing the rate of their breakdown. These include St. John’s wort and some steroids.
Nursing Care Plan for Patients on Anticoagulants
- Possible Nursing Diagnoses
- Risk for Bleeding related to anticoagulant therapy
- Decreased Cardiac Output related to potential for bleeding and/or cardiac arrhythmias
- Risk for Injury related to clot-dissolving properties of anticoagulant therapy
- Fatigue related to anticoagulant drug side effects
- Deficient Knowledge related to drug action and side effects
|Assess the patient for signs and symptoms of atrial fibrillation or blood disorders. Check if the patient has been prescribed anticoagulants post-surgery.||To confirm the indication for administering anticoagulants.|
|Check the patient’s allergy status.||Previous allergic reaction to anticoagulants may render the patient unable to take them. Alternatives to anticoagulants should therefore be considered in case of allergy.|
|Assess if the patient is pregnant or lactating.||Anticoagulants are generally not prescribed for pregnant women as these drugs can potentially harm the fetus or newborn. However, several common anticoagulants are generally safe while breastfeeding while other anticoagulants are not recommended. Therefore, it is important for the patient to seek advice from her physician regarding the safety of the specific anticoagulant prescribed to her.|
|Check for the status of peripheral veins prior to cannulation and administration of intravenous anticoagulants. If administering oral anticoagulants, assess the patient’s mucous membranes and his/her ability to swallow.||To check for any potential problems with administration, hydration, and absorption.|
To ensure that the right form of anticoagulants is given through the right route.
|Check the patient’s medical history for:Stomach ulceration or any active bleeding ulcersHemorrhagic strokeHemophilia or any other bleeding disordersCerebral aneurysm||Anticoagulants are contraindicated in patients with the mentioned diseases.|
|Obtain a list of current medications and their doses from the patient or carer.||The patient’s current medications that include antiplatelets or Serotonin Reuptake Inhibitors (SSRIs) should be reviewed and must not be taken in conjunction with anticoagulants due to increased risk for bleeding.|
|Obtain blood samples and monitor platelet counts as well as coagulation levels (INR, PT, and PTT).||To ensure that the anticoagulant dosing is in line with the target therapeutic range, thus reducing the risk of bleeding. Increased INR, PT and PTT in a patient on anticoagulant therapy means an increased risk for bleeding. This calls for an immediate review of the right dose for the patient.|
|Consider the patient’s age when calculating the dose for anticoagulants.||Children are prescribed anticoagulants using careful dose calculation that may be different from adult calculation.|
Nursing Planning and Intervention
|Administer oral anticoagulants either before or after meals, but always at the same time of the day.||To ensure optimal absorption and therapeutic action by anticoagulants. Anticoagulants are usually given in the evening, but latest research says that there is no significant difference of taking anticoagulants in the morning or evening, as long as they are taken on the same time of the day in the correct form and dosage.|
|Educate the patient about the action, indication, common side effects, and adverse reactions to note when taking anticoagulants. Instruct the patient on how to self-administer oral anticoagulants.||To inform the patient on the basics of anticoagulants, as well as to empower him/her to safely self-administer the medication.|
|Recommend switching from IV anticoagulant to subcutaneous or oral anticoagulant to the doctor when the therapeutic range has been reached.||To facilitate safe transition of anticoagulation therapy from clinical management to patient self-management before discharge.|
|Collect urine and stool samples for occult blood testing.||Patients on anticoagulant therapy may not show apparent signs and symptoms of bleeding, thus checking for the presence of blood in the stool or urine is an important nursing intervention.|
|In the event of a bleeding episode due to excessive use of anticoagulants, administer the appropriate antidote as prescribed.||Vitamin K is currently used for warfarin overdose.Protamine sulfate is currently used for heparin overdose.|
|Advise the patient to avoid drinking cranberry juice while taking warfarin.||Cranberry juice can increase the anticoagulant or blood thinning effect of warfarin.|
|Educate the patient to be consistent in incorporating green leafy vegetables, liver, and chickpeas in the diet.||Foods rich in vitamin K such as green leafy vegetables (broccoli, parsley, kale, spinach, etc.), liver, and chickpeas can cause interference with the therapeutic action anticoagulants, particularly decreasing their potency.|
|Encourage the patient to limit alcohol consumption to 1 to 2 units per day while on anticoagulant therapy.||Alcohol may increase the risk of bleeding while the patient is on anticoagulant therapy.|
|Inform the patient to use soft-bristled toothbrush and electric razor for hygiene purposes.||To prevent injury and lower the risk for bleeding while on anticoagulants.|
|Ask the patient to repeat the information about anticoagulants.||To evaluate the effectiveness of health teaching on anticoagulants.|
|Monitor the cardiovascular and neurological status of the patient.||To ensure that the anticoagulants did not cause any cardiac arrythmias, or other adverse events to the patient.|
|Monitor kidney and liver function through blood tests for older adults.||Older adults are at risk of drug toxicity due to long-term anticoagulant use.|
|Monitor the patient’s response to anticoagulants in terms of side effects or adverse effects.||To check if the anticoagulants are effective, the dose needs to be adjusted, or the drug should be stopped and changed to an alternative treatment.|
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Silvestri, L. A. (2020). Saunders comprehensive review for the NCLEX-RN examination. St. Louis, MO: Elsevier. Buy on Amazon
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