Pain killers

Cancer pain

THE REASONS

  1. infiltration or compression by a tumor of various structures or complications (eg, pathological vertebral fracture due to malignant metastasis)
  2. cancer cachexia (a common cause of musculo-fascial pain)
  3. oncological treatment (for example, plexopathy after radiotherapy, pain syndromes after mastectomy, neuropathy after chemotherapy)
  4. other related (eg, headache, coronary pain)

TREATMENT

General rules of Pharmacotherapy

  1. Introduce drugs p / o, and if this is impossible (due to nausea, vomiting, swallowing disorders) – p / c or transdermally (dying patients, when they can no longer swallow drugs, change the p / o introduction to p / c do not start transdermal treatment).
  2. In case of constant pain, administer the drugs regularly (and not only in case of increased pain), with an interval of time dependent on the pharmacokinetics of the drug; the patient must be provided with an immediate-release drug in order to be able to take it in case of breakthrough pain (that is, it appears, despite the regular use of an analgesic).
  3. Use drugs according to the analgesic ladder → fig. 1-1. For pain of low intensity, start treatment with paracetamol or / and non-steroidal anti-inflammatory drugs (NSAIDs), if there are no contraindications. If the effect is unsatisfactory, go to a higher rung of the ladder. In cancer patients suffering from severe pain, usually use opioids, regardless of the mechanism of pain. At each stage of the analgesic ladder, consider the indications for the use of co-analgesics, as well as drugs that reduce side effects. At stages 2 and 3 of the analgesic ladder, consider the further use of a non-opioid analgesic, because it enhances the analgesic effect of opioids and inhibits the development of opioid tolerance.

Non-opioid analgesics

  1. Paracetamol: acts quickly (15–30 min) and briefly (up to 4–6 h); Max. daily dose in an adult without an increased risk of hepatotoxicity – 4 g (in the elderly – 3 g, according to some experts – 2 g), the risk of hepatotoxicity is increased including in cachectic patients and those who refuse to eat, in alcoholics.
  2. NSAIDs: the strongest analgesic effect in receptor pains with an inflammatory reaction, bone and muscle fascia pain. Assess the risk of cardiovascular, digestive and kidney side effects; consider prevention of complications of the digestive system → Sec. 4.7.

Weak opioids

  1. Codeine: in the case of the use of the drug containing only codeine – initially p / o eg. from 20 mg every 4 hours (10–20 mg every 4–6 hours), if necessary, gradually increase the dosage to max. 240 mg / day.
  2. Dihydrocodeine: p / o, starting from 60 mg every 12 hours, if necessary, gradually increase to 120 mg every 12 hours.
  3. Tramadol: initially, usually 25–50 mg every 8–6–4 h of a p / o as part of an immediate-release preparation (Plazadol, Tramadol, Tramal), in the elderly, cachectic and / or with impaired renal or liver function, start with 12 , 5-25 mg in the form of drops; if necessary, increase the dose by 30–50% every 24 hours to max. 400 mg / day (in patients aged> 75 years, do not exceed a dose of 300 mg / day). Use sustained-release preparations every 12 hours (Tramadol retard, Tramal retard) or 1x day. Causes constipation to a lesser extent than codeine and dihydrocodeine, but often at the beginning of treatment causes nausea and / or vomiting. In addition, it inhibits serotonin reuptake and can cause serotonin syndrome if used in conjunction with other drugs that increase serotonin levels. Do not use with MAO inhibitors and for 14 days after their withdrawal, as well as in case of terminal renal failure (GFR ≤ 10 ml / min / 1.73 m2) and in patients with poorly controlled epilepsy.
  4. Small doses of morphine (≤30 mg / day), oxycodone (≤20 mg / day) or hydromorphone (≤4 mg / day): according to the recommendations of EAPC (2012), are considered as opioids of the 2-step analgesic ladder. Example: morphine in an immediate-acting preparation in small initial doses (eg, 2.5 mg every 4 hours p / o) in a patient with pain and shortness of breath, as it is the drug of choice for alleviating shortness of breath.