Hematopoietic growth factors: Nursing pharmacology

Hematopoietic agents are medications used to increase the production of different types of blood cells including white blood cells, red blood cells, and platelets.

They are mainly used in disorders that decrease the levels of specific blood cells, but they are also used after treatments like chemotherapy, or radiation therapy, that suppresses the bone marrow.

Now, hematopoietic growth factors act like analogs or synthetic versions of the various physiological growth factors produced by the body.

These include granulocyte colony-stimulating factor or G-CSF, granulocyte-macrophage colony-stimulating factor or GM-CSF, thrombopoietin agents, and erythropoietin stimulating agents or ESAs.

Let’s start with G-CSF analogs, which include filgrastim and pegfilgrastim. These medications can be administered intravenously and subcutaneously and work by increasing the production of neutrophils in the bone marrow.

So they’re used to reduce the risk of infections on account of low neutrophil counts, which can be associated with leukemia, myelofibrosis, or severe, chronic neutropenia.

Another indication is for clients undergoing treatments that inhibit neutrophil production, like chemotherapy or radiation therapy for solid tumors or hematologic malignancies, as well as those receiving bone marrow transplantation.

Finally, G-CSF analogs can be used in hematopoietic stem cell transplantation, where progenitor cells are mobilized from the bone marrow by G-CSF, and then collected from the peripheral blood.The most commonly reported side effects of G-CSF analogs are nausea and bone pain, resulting from the high production of new neutrophils in the bone marrow.

Other side effects include fever, fatigue, skin rashes, coughing, dyspnea or chest pain. Less commonly, alopecia or hypertension can also occur, as well as diarrhea or severe hypersensitivity reactions.

Very rarely, G-CSF analogs might cause the spleen to become enlarged and rupture. In clients with sickle cell disease, sickle cell crises have also been reported.In terms of contraindications, filgrastim should not be administered to clients with hypersensitivity to Escherichia coli–derived proteins, while pegfilgrastim should not be given within 14 days before and 24 hours after the administration of cytotoxic chemotherapy.Moving on to GM-CSF analogs, the most commonly used one is sargramostim which is given intravenously.

Once administered, it stimulates myeloid progenitors for all types of white blood cells, and it causes them to divide and differentiate into monocytes or macrophages, neutrophils, basophils, and eosinophils.

Sargramostim is often used to boost myeloid precursor production and maturation after a client undergoes a bone marrow transplant or in case of failure or delayed engraftment of the bone marrow transplant.

Other uses for sargramostim include increasing the myelocyte derived white blood cell count following chemotherapy or radiation therapy.

And just like G-CSF analogs, sargramostim can be used to mobilize progenitor cells in the peripheral blood for hematopoietic stem cell transplantation.Now, with sargramostim, a side effect called the “first dose effect” can occur, when the client can experience hypotension, tachycardia and flushing.

Other most common side effects include fever, fatigue and bone pain, as well as dermatological reactions, like rashes and itching; cardiovascular reactions like hypertension; gastrointestinal reactions like diarrhea, nausea and vomiting; as well as various metabolic disturbances like hyperglycemia.

It can also cause a problem known as capillary leak syndrome, where fluids leak from the capillaries into the surrounding tissue, causing severe edema.

More severe side effects associated with sargramostim are sepsis, arrhythmias, liver and kidney dysfunction.Contraindications of sargramostim include known hypersensitivity to yeast products.

It should also not be administered if there are excessive leukemia myeloid blast cells in the bone marrow or peripheral blood, as well as within 24 hours after the administration of chemotherapy or 12 hours after the last dose of radiation therapy.

Sargramostim should also be used with caution during pregnancy and in clients with preexisting lung, heart, kidney, or liver disease.Now let’s switch gears to look at thrombopoietin agents, which are medications that increase platelet count.

Some examples include TPO receptor agonists, like romiplostim, avatrombopag and eltrombopag, which are used in the management of immune thrombocytopenic purpura, or ITP; myelodysplastic syndrome; or aplastic anemia.

Romiplostim is administered subcutaneously, while avatrombopag and eltrombopag can be given orally. Once administered, they work by activating TPO receptors on the surface of megakaryocyte cells, which leads to increased platelet production.

Unfortunately, these medications do come with side effects. Romiplostim, for example, can cause headaches, respiratory infections and GI disturbances like nausea, vomiting and diarrhea; as well as rashes, joint pain, and fever.

Avatrombopag and eltrombopag, on the other hand, can cause acute tongue twisting in those prescribing them - just kidding!

On a more serious note, eltrombopag does come with a boxed warning for hepatotoxicity. Other common side effects of eltrombopag include upper respiratory tract infections and gastrointestinal disturbances; while for avatrombopag, they include respiratory infections, gingival hemorrhages, bruising, fatigue, headache and joint pain.

Now, as far as contraindications go, remember that TPO receptor agonists come with their risks. Romiplostim should be used with caution during pregnancy or breastfeeding, or in clients who are receiving other therapies for ITP, while both avatrombopag and eltrombopag should be used with caution in clients with hepatic disease or a known risk for thromboembolism.

Lastly, there are erythropoietin stimulating agents, or ESAs for short, like epoetin alfa and darbepoetin alfa, which are used to treat anemia secondary to chronic kidney disease or chemotherapy.

Epoetin can also be used to correct anemia caused by other medications, like the HIV drug zidovudine. Both epoetin alfa and darbepoetin alfa can be administered intravenously or subcutaneously and work by stimulating the production of new red blood cells.

It’s important to note that several weeks of therapy are required before erythrocyte counts rise, so these medications are not an alternative to transfusing blood.

In general, ESAs are well-tolerated medications. However, they come with some boxed warnings, including an increased risk of myocardial infarction, stroke and thromboembolism, as well as an increased risk of death in some clients with chronic kidney disease.

They also have a boxed warning for shortening survival rate in certain cancers, so the lowest dose possible should be used.

The final boxed warning is if epoetin alfa is used for perisurgical clients, prophylaxis for deep vein thrombosis, or DVT, should be used.

Other common side effects include hypertension, headache, fever, weakness or fatigue, dizziness, coughing, joint pain, and gastrointestinal side effects, like abdominal pain, nausea and diarrhea.

The client can also experience injection site skin reactions like pain, swelling, or redness at the site. Potentially life-threatening side effects, such as seizures or hyperkalemia, can also occur but they are rare.

Regarding contraindications, ESAs should not be used in clients with uncontrolled hypertension.Now, if a client diagnosed with anemia is prescribed epoetin alfa, start by performing a baseline assessment of your client's current symptoms like dizziness, fatigue, weakness, and shortness of breath.

Then, assess their weight, vital signs, and SpO2. Lastly, review their most recent laboratory test results, such as CBC, hemoglobin, hematocrit, ferritin, transferrin, iron, and renal function tests.Next, explain to your client that the medication will help treat their anemia by stimulating the production of red blood cells, and that it is administered subcutaneously on a regular schedule, three times each week.

Then, teach your client how to draw up their medication, and demonstrate proper subcutaneous injection technique, as well as disposal of the needle and syringe.

Show them how they can self-administer the medication in the middle front part of the thigh or in the abdomen, as long as it is at least 2 inches from the navel.

Encourage them to keep track of where they inject the medication so they can rotate the injection site each time. Also, stress the importance of avoiding any area that is red, tender, hard, scarred, or bruised.

Lastly, let your client know that, during therapy, they will have to follow up with their healthcare provider regularly for periodic monitoring of their blood pressure and laboratory tests.

Then, review with your client some of the side effects they could experience during therapy, such as weakness, fatigue, or gastrointestinal side effects like abdominal pain, nausea, or diarrhea.

Emphasize the importance of seeking immediate medical attention if they experience symptoms of clotting, such as weakness on one side of the body, problems speaking or breathing, chest pain, coughing up blood, and pain or swelling in the lower extremities; as well as symptoms of hypertension like a severe headache, visual changes, or becoming very dizzy.Finally, when caring for a client with anemia receiving epoetin alfa, monitor your client’s laboratory test results and blood pressure, as well as for the development of additional side effects, and be sure to evaluate for the desired therapeutic effect of increased hemoglobin and hematocrit levels, as well as a reduction in symptoms associated with anemia.

All right, as a quick recap... Hematopoietic agents are medications used to increase the production of different types of blood cells, including white blood cells, red blood cells, and platelets.

They are mainly used in disorders that decrease the levels of specific blood cells, and can also be used after certain treatments that suppress the bone marrow, such as chemotherapy or radiation therapy.

Hematopoietic agents include G-CSF analogs, GM-CSF analogs, thrombopoietin agents, and erythropoietin stimulating agents.

When caring for a client receiving a hematopoietic agent, nursing considerations include performing a baseline assessment, and monitoring for the development of side effects, as well as for the desired therapeutic effect.

Client teaching is focused on safe self-administration and recognizing side effects that should be reported to their healthcare provider.

Therapeutic effect, playing teaching is focused on Steve self-administration and recognizing side effects. That should be reported to