From the Guidelines
NTX (Naltrexone) is an opioid antagonist medication primarily used to treat alcohol and opioid dependence by blocking the effects of opioids and reducing cravings, as noted in a study published in the American Family Physician in 2013 1. NTX is available in oral form (typically 50mg daily) and as a long-acting injectable (Vivitrol, 380mg monthly).
- The medication works by blocking the effects of opioid agonists, providing time for patients to consider the consequences of relapse and seek support.
- It has been shown to be helpful in maintaining abstinence from opioids in motivated populations, such as healthcare professionals who cannot or do not wish to take continuous opioid agonist therapy.
- However, it has had limited success in other groups and can cause hepatic injury at supratherapeutic doses, making liver function tests at baseline and every three to six months necessary.
On the other hand, CTX can refer to two different medications:
- Ceftriaxone is a third-generation cephalosporin antibiotic used to treat various bacterial infections, typically administered intravenously or intramuscularly at doses of 1-2g daily.
- Cyclophosphamide is an immunosuppressive chemotherapy drug used to treat certain cancers and autoimmune disorders, with dosing that varies by condition and patient factors. These medications work through different mechanisms - Naltrexone blocks opioid receptors in the brain, Ceftriaxone disrupts bacterial cell wall synthesis, and Cyclophosphamide interferes with DNA replication in rapidly dividing cells.
- Side effects and contraindications differ significantly between these medications, so they should only be used under appropriate medical supervision for their specific approved indications, as supported by the study published in the American Family Physician in 2013 1.
From the FDA Drug Label
Naltrexone hydrochloride, an opioid antagonist, is a synthetic congener of oxymorphone with no opioid agonist properties. Cyclophosphamide is a pro-drug that is activated by cytochrome P450s
NTX and CTX are abbreviations for:
- NTX: Naltrexone, an opioid antagonist
- CTX: likely refers to Cyclophosphamide, a pro-drug activated by cytochrome P450s, or possibly Ceftriaxone, which is not mentioned in the provided drug labels 2 3
From the Research
NTX (Naltrexone)
- Naltrexone is an opioid receptor antagonist that blocks the reinforcing effects of opioids and reduces alcohol consumption and craving 4, 5.
- It has no abuse potential, mild and transient side effects, and thus appears an ideal pharmacotherapy for opioid dependence 4.
- Naltrexone is also found to relieve craving for alcohol and is one of few FDA-approved medications for treatment of alcohol use disorder (AUD) 5.
- The therapeutic effect of NTX treatment in AUD may in part be due to direct actions on kappa-opioid receptors and in part due to its effect on the surrounding lipid environment 5.
CTX (Ceftriaxone/Cyclophosphamide)
- There is no information available on CTX (Ceftriaxone/Cyclophosphamide) in the provided studies.
- The studies only discuss Naltrexone (NTX) and its effects on opioid and alcohol dependence, but do not mention CTX.
Combination Therapies
- Combining naltrexone with other medications, such as prazosin, may be more effective in decreasing alcohol drinking than either drug alone 6.
- Extended-release naltrexone (XR-NTX) has been shown to improve quality of life in alcohol-dependent patients, particularly in the domains of mental health, social functioning, general health, and physical functioning 7.