Platinum-based agents: Nursing pharmacology

Platinum-based agents, sometimes called platins, are medications that are mainly used to treat cancer. Broadly speaking, they are part of the bigger “alkylating-like agents” category, and they are primarily used in the treatment of solid tumors, like colon, rectum, lung, ovarian, uterus, testicular, and bladder cancer.Now, the most commonly used platins include cisplatin, carboplatin and oxaliplatin, which are administered intravenously.

Once administered, platins act as cell-cycle phase nonspecific agents, which means they work by causing damage to the DNA of rapidly dividing cancer cells in all phases of the cell-cycle, ultimately causing their death.

There are three ways they do this. First, they can attach an alkyl group to one of the DNA bases of cancer cells.

Repair enzymes recognize there’s something wrong, so they jump in to replace the alkylated bases and cause DNA fragmentation, which eventually results in DNA damage and cancer cell death.

The second mechanism is the crosslinking of DNA, which means the alkylating agent links two DNA bases together, forming cross-bridges.

Cross-linking prevents DNA from being separated for essential cell processes, like replication or transcription, eventually resulting in cancer cell death and stopping the multiplication of cancer cells.

Cisplatin and carboplatin employ both these mechanisms to exert their antineoplastic effect, while oxaliplatin only seems to act through crosslinking of DNA.

Additionally, cisplatin and carboplatin also act through a third mechanism, which is to inhibit the enzymes involved in cell replication and multiplication.Unfortunately, platinum-based agents also act on healthy rapidly dividing cells, including those in the skin, bone marrow, and gastrointestinal tract.

As a result, these medications can often cause several side effects, such as alopecia, skin rash, and photosensitivity, as well as nausea, vomiting.

Vomiting is actually a boxed warning for cisplatin and carboplatin. In addition, these medications can cause bone marrow suppression, which is yet another boxed warning for cisplatin and carboplatin, and can manifest as anemia, thrombocytopenia and increased risk of bleeding, and leukopenia, which increases the risk of infections.

Also remember that all platins are vesicants, so another side effect is that they can all cause the formation of blisters and tissue necrosis if the drug leaks out of the vein into surrounding tissues.

Two more boxed warnings for cisplatin include neurotoxicity, specifically peripheral neuropathy, as well as nephrotoxicity.

Remember that peripheral neuropathy is another common side effect for oxaliplatin, and carboplatin can also cause nephrotoxicity.

For more specifics, cisplatin and carboplatin can cause ototoxicity, which can present as tinnitus, or ringing in the ears, or even hearing loss, and both carboplatin and oxaliplatin have boxed warnings for potentially fatal hypersensitivity reactions.As far as contraindications go, platinum-based agents shouldn’t be used during pregnancy and breastfeeding because they are teratogens, meaning they disrupt fetal development, which can lead to birth defects.

They should also be used with caution in clients with renal disease, and can cause temporary elevation of liver function tests.

Carboplatin is also contraindicated in clients with significant bone marrow suppression or bleeding.Now, when a client with ovarian cancer is prescribed cisplatin, start by performing a baseline assessment, including weight, vital signs, and their current symptoms, such as pelvic or abdominal pain, vaginal bleeding, fatigue, early satiety, and bloating.

Then, review their most recent laboratory test results such as CBC, renal and liver function tests, electrolytes, and confirm a negative pregnancy test as needed.

Lastly, review diagnostic tests, including cancer antigen 125, or CA 125 for short; and transvaginal ultrasound results.

Then, explain to your client that the medication will help to treat ovarian cancer, and that it will be administered intravenously every 3 to 4 weeks.

Then, let them know that severe nausea and vomiting is a common side effect, and it can be managed with prescribed antiemetics as well as increasing their fluid intake.

Also, explain how the medication increases their risk for infection; and stress the importance of including infection prevention measures in their daily routine, such as frequent hand hygiene, avoiding large crowds, people with infections, and live attenuated vaccines; and instruct your client to notify their healthcare provider if they develop symptoms of an infection, such as fever, sore throat, or other flu-like symptoms.

In addition, let them know that their medication may cause an increased risk of bleeding, and that they should report any unusual bleeding, such as easy bruising or bruises that appear without a reason, as well as vomiting blood, stools that are red, black, or tarry in appearance, or abnormal vaginal bleeding.

Other important side effects to report include symptoms of renal impairment, which could manifest as decreased urine output, blood in the urine, or unusual weight gain; as well as neurotoxicity, which could cause peripheral neuropathy with numbness and tingling of their hands or feet; and ototoxicity, which could cause dizziness, tinnitus, or hearing loss.

Lastly, remind them to use a reliable form of contraception during treatment.Now, when preparing to administer cisplatin, confirm that they have a patent IV, port-a-cath, or PICC line in place, that emergency medications and equipment are readily available, and ensure your client is well hydrated with the ordered intravenous fluids.

Prior to starting the infusion, premedicate your client with the ordered antiemetic 30 to 60 minutes before you begin the infusion.

Then, verify the prescribed dose in mg/m2; and lastly, be sure to always wear gloves or other protective clothing when handling the medication.

As the medication infuses, continue to monitor your client’s vital signs, and watch closely for signs and symptoms of extravasation like blistering and pain.

If extravasation is suspected, stop the infusion immediately, elevate the extremity, and administer subcutaneous sodium thiosulfate.

In addition, instruct your client to let you know if they experience ringing or buzzing in their ears, as well as dizziness or headache during the infusion.

Also monitor your client for signs of a hypersensitivity reaction, including shortness of breath, difficulty swallowing or breathing, or an unusual rash.

If a reaction does occur, be prepared to administer emergency medications as ordered. Lastly, be sure to monitor for nephrotoxicity by keeping a close eye on their fluid intake and output.

Finally, during treatment with a platinum-based agent like cisplatin, closely monitor your client’s CBC and renal function, keep an eye out for the development of side effects, and be sure to evaluate for the desired therapeutic effect of decreased symptoms associated with ovarian cancer.

Alright, as a quick recap… Platinum-based agents are medications that are mainly used in the treatment of solid tumors, such as colon, rectum, lung, ovarian, uterus, testicular, and bladder cancer.

These medications include cisplatin, carboplatin, and oxaliplatin, which are administered intravenously, and work by causing damage to the DNA of rapidly dividing cancer cells in all phases of the cell-cycle, ultimately causing their death.

Unfortunately, platinum-based agents also act on healthy rapidly dividing cells, including those in the skin, bone marrow, and gastrointestinal tract, leading to side effects.

These medications can also cause neurotoxicity, nephrotoxicity, and ototoxicity. When caring for a client taking a platinum-based agent, nursing considerations include performing a baseline assessment, monitoring for the development of side effects, as well as for the desired therapeutic effect.

Client teaching is focused on what to expect during treatment, as well as learning to recognize side effects and when