Palliative drug therapy



Palliative drug therapy





Almost invariably, dying patients receive many drugs and undergo various degrees of organ failure before reaching the end of life. Both of these issues will complicate your ability to manage the patient’s symptoms and maximize his level of comfort through the dying process. This is particularly true when the patient is a child, for whom drug dosages aren’t always established. (See Drug precautions in children.)

Naturally, the more drugs a patient is receiving, the more likely he is to experience adverse effects and drug interactions. Plus, physiologic changes common to dying patients — such as a slowed metabolism, impaired renal or hepatic function, poor circulation, and an impaired central nervous system (CNS) — may raise the risk of drug accumulation and toxicity. Also, dehydration
and electrolyte imbalances can affect how drugs are absorbed by the body.



Drug precautions in children

Children absorb, metabolize, and excrete drugs differently than adults do. These differences may alter the amount of a drug needed to produce a therapeutic effect and the amount that causes toxic effects. Because standardized dosages commonly aren’t available for children, follow these tips:



  • Evaluate the child’s kidney and liver function.


  • Avoid using the child’s age to make assumptions about organ system development.


  • In lean children, use height to calculate doses.


  • In larger or obese children, use body surface area or the next higher dose.

Despite these challenges, with carefully orchestrated drug therapy and close attention to the pharmacokinetics and pharmacodynamics of the drugs involved, you can ease many or all of the symptoms experienced by dying patients. And by preparing and teaching caregivers how to use an emergency drug kit, you can ensure that even a patient dying at home can receive timely customized palliative drug therapy. An emergency kit contains a selection of drugs commonly needed by dying patients and is available for immediate use as symptoms arise. (See Contents of an emergency kit.)

Symptoms experienced most often by patients in end-of-life care include pain, fatigue, dyspnea, excessive respiratory secretions, nausea and vomiting, constipation, and diarrhea. This chapter offers a quick overview of the best ways to manage these symptoms through careful drug therapy.



Contents of an emergency kit






































Drug Form Uses
morphine
Alternative: oxycodone (Roxicodone, Oxyir)		 Oral, sublingual, or rectal Pain
Dyspnea
lorazepam (Ativan)
Alternative: diazepam (Valium)		 Oral, sublingual, or rectal Seizures
Anxiety
Muscle spasm
Agitation
hyoscyamine (Levsin) hyoscyamine: oral or sublingual Excess secretions
Alternative: scopolamine
(Scopase, Transderm Scōp)		 transdermal patch or oral Nausea and vomiting if patient has GI obstruction
haloperidol (Haldol) Oral or rectal Agitation
Nausea and vomiting
lorazepam (Ativan), diphenhydramine (Benadryl), halo-peridol (Haldol), and meto-clopramide (Reglan), compounded as ABHR Rectal or troche Nausea and vomiting
prochlorperazine (Compazine) Oral or rectal Nausea and vomiting
phenytoin (Dilantin) Oral Seizures



Pain

Pain is the problem that most dying patients and their families worry about most. When it’s inadequately managed, pain can affect a person’s ability to sleep, cope, and relate to others. It dramatically affects quality of life, and it will affect the patient’s quality of death.

Although many nondrug treatments — such as massage, relaxation exercises, and acupuncture — can help reduce a patient’s pain, the mainstay of pain management is drug therapy. Depending on the severity and cause of the pain, some drugs may offer more benefits or fewer adverse effects than others. Drugs commonly used to manage pain in a dying patient include nonopioids, opioids, and some other drugs that are effective in certain situations. Keep in mind that some common drugs shouldn’t be used at all during end-of-life care.


Nonopioids

Usually, pain control starts with a nonopioid, such as acetaminophen or a nonsteroidal anti-inflammatory drug (NSAID). (See Common nonopioid analgesics, pages 64 and 65.) Acetaminophen’s mechanism of action isn’t known exactly, but the drug probably works centrally. Aspirin and NSAIDs inhibit cyclooxygenase, which decreases prostaglandin production and, in turn, pain and inflammation. Acetaminophen and opioids decrease pain but not inflammation.

Acetaminophen has few side effects, but the dosage may be limited by hepatic impairment, which may increase the risk of hepatotoxicity and liver damage. NSAIDs may increase the risk of peptic ulcer, renal failure and edema, allergic reactions, and hearing loss. They also may increase the risk of hemorrhage.

LIFESPAN Because of its safety profile, acetaminophen is the preferred drug for treating chronic pain in elderly patients. Don’t give more than 3 grams daily, and avoid acetaminophen entirely if the patient consumes excessive amounts of alcohol. Make sure the patient’s liver function is checked periodically.

Consider these age-related changes whenever you add or adjust a drug:



  • Renal and hepatic function may be decreased even if an elderly patient isn’t in end-stage organ failure.


  • An age-related decrease in lean body mass may influence drug metabolism and availability. If the drug is lipid-soluble (such as fentanyl), it may have a slightly delayed onset and increased risk of accumulation; if it’s water-soluble (such as hydromorphone and morphine), the opposite may occur.


  • Decreased gastric motility may delay absorption of NSAIDs and increase their adverse gastrointestinal (GI) effects.



Opioids

If the patient has severe pain, he’ll need an opioid. Morphine is the archetypal drug in the class. It’s highly effective and available in many forms, including sustained-release capsules, immediate-release tablets, concentrated liquids, suppositories, and subcutaneous and intravenous injections.

Morphine and similar drugs (such as oxycodone, hydrocodone, diamorphine, and fentanyl) all have a similar influence on cerebral opiate receptors. They also may produce similar adverse effects, such as these:



  • Up to 1 in 3 patients starting morphine may have nausea and vomiting. Usually, it abates after a short course of antiemetics.


  • Pruritus may develop; if it does, you may need to switch the patient to a different opioid.


  • Constipation develops in almost all patients who take opioids. Usually, a laxative — such as lactulose, senna, or docusate — is prescribed along with the opioid.


  • Morphine and other opioids may cause respiratory depression, hallucinations, and sedation, all of which may be distressing for both patient and family. As the patient adjusts to the dosage, this effect usually remits, although it may recur briefly whenever the dosage is increased. Make sure to differentiate this drug-related effect from progression of the patient’s disease.

Opioid doses may be limited by toxicity, which you should suspect if the patient is confused and has myoclonic jerks and pinpoint pupils. However, as long as toxicity isn’t evident, there’s no ceiling for the opioid dosage in a dying patient. (See Merciful meds, page 66.) When used appropriately, opioid analgesics are safe and effective, with little risk of addiction.



Alert

Many analgesics combine an opioid with a nonopioid to increase pain relief. A common combination is Acetaminophen and codeine. For a dying patient in severe pain, the limiting factor for many of these combination drugs is the nonopioid part. For the patient to receive enough benefit from the opioid, he’d need an overdose of the nonopioid component. These drugs are best used for mild to moderate pain.


Other drugs

Pain comes in many forms and from many sources. Likewise, drugs used to relieve pain work by many different mechanisms. (See How drugs reduce pain. page 67.) Matching the drug’s mechanism of action with the type of pain you’re trying to relieve can increase your success. In fact, some types of pain respond best to drugs that aren’t even known as typical analgesics. For example:



  • In a patient with brain cancer, pain may stem from pressure inside the skull. This pain may respond best, initially at least, to high doses of dexamethasone (Decadron), a corticosteroid.




Common nonopioid analgesics




































































Class Generic name Available forms and strengths Starting dosage Maximum daily amount
P-Aminophenol derivatives acetaminophen Tablets: 80 mg, 325 mg, 500 mg, 650 mg
Suppositories: 120 mg, 125 mg, 325 mg, 600 mg, 650 mg
Liquid: 160 mg/5 ml, 500 mg/15 ml
Elixir: 80 mg/2.5 ml, 120 mg/5 ml, 160 mg/5 ml, 325 mg/5 ml		 2,600 mg/day given q 4 to 6 hours 6,000 mg
Salicylates aspirin Tablets: 325 mg, 500 mg, 650 mg, 800 mg
Suppositories: 120 mg, 200 mg, 300 mg, 600 mg		 2,600 mg/day given q 4 to 6 hours 6,000 mg
choline magnesium trisalicylate Tablets: 500 mg, 750 mg, 1,000 mg
Liquid: 500 mg/5 ml		 1,500 mg for one dose; then 1,000 mg q 12 hours 4,000 mg
Proprionic acids ibuprofen Tablets: 100 mg, 200 mg, 300 mg, 400 mg, 600 mg, 800 mg
Suspension: 40 mg/ml, 100 mg/5 ml		 1,600 mg/day given q 4 to 6 hours 3,200 mg
naproxen Tablets: 250 mg, 375 mg, 500 mg
Suspension: 125 mg/ml		 500 mg/day given q 8 to 12 hours 1,500 mg
Acetic acids indomethacin Capsules: 25 mg, 50 mg
Extended-release: 75 mg
Suspension: 25 mg/5 ml
Suppositories: 50 mg		 200 mg/day given q 8 to 12 hours 200 mg
diclofenac Tablets: 25 mg, 50 mg, 75 mg, 100 mg
Extended-release: 100 mg		 150 mg/day given q 8 to 12 hours 225 mg
nabumetone Tablets: 500 mg, 750 mg 1,000 mg/day given q 24 hours 2,000 mg
Pyranocarboxylic acids etodolac Capsules: 200 mg, 300 mg
Tablets: 400 mg, 500 mg
Extended-release: 400 mg, 600 mg		 600 mg/day given q 6 to 8 hours 1,200 mg
Cyclooxygenase-2 inhibitors celecoxib Capsules: 100 mg, 200 mg, 400 mg 200 mg/day given q 12 to 24 hours 800 mg

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Aug 1, 2016 | Posted by in NURSING | Comments Off on Palliative drug therapy

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