Pentazocine (Talwin) is an old agonist-antagonist opiate now available as a generic at a cost of about $1 per pill.  It's primary effect is on the kappa-opioid receptor, not the mu-opioid receptor, although it might be a partial mu-receptor agonist, like buprenorphine.  It has a lower abuse potential unless injected IV.  Thus, it is available as a class IV narcotic, instead of a class II narcotic, like full agonists.  

Sanofi-Synthelab also promotes it's Talacen, a combination of pentazocine 25 mg plus acetaminophen 650 mg, also available as a generic. Like all other narcotics, there is no reason to for pain relief.  In the studies below, pentazocine did worse than non-narcotics 9 times, equal but with more side-effects four times, and totally equal twice.  In no case, did pentazocine to better.  Pentazocine's score is 0 wins, 2 ties, and 13 losses.  It's a loser. 

An interesting combination is available since 1983 combining pentazocine with naloxone.  Pentazocine improves opiate withdrawal, but is a morphine antagonist and can cause withdrawal in a narcotic addict not already in withdrawal.  It this respect, it is similar to buprenorphine.  Naloxone might accentuate its pain relieving effect according to one dental study.  The naloxone should block IV abuse, a problem in the late 1970's ("T's and blues" IV).  It is called Talwin-NX and is also available as a generic for about $156 for 90 tablets at Walgreens.  The generic may be available more cheaply elsewhere, since I am able to purchase the generic wholesale for just $58.50 for 90 tabs.  Pentazocine may not legally be used to maintain opiate addicts, since it is a controlled substance.  Only Suboxone and methadone are approved.  Tramadol can be used for opiate maintenance since, although it is an opiate, it is not a controlled substance. 

Addiction can occur to the oral form, but it made up only 3% of pentazocine addicts in one study and withdrawal was mild.  Whether it could be used like Suboxone is unknown.  One disadvantage is that it is shorter acting (3 vs. 37 hours), but an advantage is that it may be less expensive and much more easily available, since it is only a class IV narcotic.  Also, many insurances will pay for Talwin NX, but not for Suboxone.  In the bizarre modern world, highly addictive opiates which are very poor pain relievers are less regulated and much more likely to be paid for by insurance than Suboxone, the drug to treat the addiction which these opiates cause.

In previous pentazocine addicts, those that used the combination reported half the level of usage as they had on pentazocine alone (Int J Addict 1988 Feb;23(2):217-26).  It can be injected with two prior pentazocine addicts reporting no difference in euphoria and the third becoming psychotic after each injection (Int J Addict).  In another reported case, the opiate addict went immediately into withdrawal, as expected.  Cases of pentazocine mentions in emergency rooms dropped by 70% with the introduction of the combination.  Like buprenorphine, the withdrawal from pentazocine is less severe than with full agonists.  Buprenorphine does bind to the mu-receptor site very powerfully, while pentazocine is only slightly more powerful in binding than morphine (J Pharm Exp Ther 1985 Jun;233(3):735-40).

Plain pentazocine should be pulled off the market unless some manufacturer can show that pentazocine is significantly better than non-addictive alternatives.  Of course, in view of the research already done, there's no way that it could ever meet that standard.  However, in view of its highly addictive nature when injected IV, pentazocine should be required to have some added benefit to offset the harm it does not society.  I think that pentazocine-naloxone might have a place in pain management, when patient cannot take NSAIDs and have failed on acetaminophen and tramadol.  It is definitely not as bad as full opiates.

If a doctor wants to give you plain pentazocine (Talwin), print out this webpage and give it to him.  Even Talwin NX is an inferior pain medication and should be avoided unless you have problems with both acetaminophen and NSAIDs.  If you doctor still insists on giving you a narcotic, get another doctor.  If a doctor gave you pentazocine and you became addicted and suffered some unfortunate consequence, the doctor and the narcotic manufacturer could be liable for malpractice.  Also, consider whether you should report the doctor to the state licensing board.  In view of the research, prescribing pentazocine is or at least should be ruled malpractice.  

Doctors are responsible for knowing whether or not narcotics are necessary.  This research is readily available to anyone with a computer and an internet connection.  Just go to Pubmed, and enter "pentazocine and double-blind."  

Biliary Colic: Pentazocine Inferior to NSAID Flurbiprofen: In a DB study of 84 adults with intense biliary colic pain, the NSAID flurbiprofen 150 mg IM resulted in less pain within 30 minutes than 20 mg of N-hyoscine butylbromide or 30 mg of pentazocine. The superior benefit continued for the entire 6 hours of the study. Pentazocine had significantly more side-effect than the other 2 treatments (p < 0.02). The efficacy of injectable flurbiprofen in the symptomatic treatment of biliary colic. Camp Herrero J, et al. Hospital Clinic i Provincial, Barcelona. Med Clin (Barc) 1992 Feb 15;98(6):212-4.

Cancer Pain: Pentazocine No Better than Ketorolac But Caused Many More Side-Effects: In a DB study of 40 patients with moderate to severe cancer pain, 10 mg ketorolac (Toradol) orally every 6 h reduced pain as well as 50 mg pentazocine for up to 7 days. Withdrawals due to adverse reactions were much less with ketorolac (p< 0.005). Ketorolac, a new non-opioid analgesic: a double-blind trial versus pentazocine in cancer pain. Estape, et al. Clinic and Provincial Hospital, Barcelona, Spain. J Int Med Res 1990 Jul-Aug;18(4):298-304. Ed: This is a surprisingly small dose of ketorolac.

Cancer: NSAID Nefopam At Least as Good with Fewer Side-Effects Than Pentazocine: In a 10-day DB study of 40 cancer patients with chronic pain, NSAID nefopam relieved pain at least as well as the narcotic pentazocine. Side efftects after nefopam were different in nature and less frequent than after pentazocine. Analgesia with mild side effects. Schietzel M. Fortschr Med 1977 Dec 1;95(45):2743-6.

Cancer Pain: NSAID Flupirtine Better than Pentazocine with Fewer Troublesome Side-Effects in Short, Small Study: In a 1-week DB study of 52 adults with "severe" to "very severe" cancer pain, flupirtine 100 mg (a centrally-acting analgesic) did better than pentazocine 50 mg with a daily dose of up to 6 capsules of each drug. Flupirtine produced more "good" or "very good" results than pentazocine (68% vs. 50%). Flupirtine fulfilled the requirements of both patients and doctors for effective cancer pain relief e.g. maintenance of the quality of life by complete or nearly complete pain remission in association with lack of abuse potential, oral dosage form and lack of disturbance of vital functions. Analgesic efficacy and safety of oral flupirtine in the treatment of cancer pain. Scheef W. Robert-Janker-Klinik, Bonn, Federal Republic of Germany. Postgrad Med J 1987;63 Suppl 3:67-70. Final evaluation demonstrated that flupirtine was significantly more effective than pentazocine in reducing pain. The incidence of side-effects was similar in both treatment groups, flupirtine, however, caused less intensive and less clinically relevant adverse reactions. Arzneimittelforschung 1985;35(1):75-7.

Cancer Pain: Pentazocine Inferior to Pirprofen: In a DB study of 168 hospitalized cancer patients, pirprofen (200 and 400 mg) was clearly better at pain relief than pentazocin (100 mg) which did no better than placebo (p< 0.05). Pirprofen 400 mg was more effective than 200 mg (p<0.05). The analgesic effect of pirprofen appeared after 30 minutes and was maximum at one or two hours. Analgesic effects of pirprofen in cancer painBuckert D. Nouv Presse Med 1982 Aug 28;11(33):2511-3.

Dental: Pentazocine Inferior to NSAID Diclofenac and Had More Side-Effects: In a DB study of 160 patients having extractions of impacted lower third molars, IV dexamethasone and IV diclofenac each did better than pentazocine and placebo with less pain within 30 minutes (p< 0.05). Pain scores on the day following surgery were also lower in the diclofenac group compared to the opioid and placebo groups (p< 0.05) but not less than those who received dexamethasone. Vomiting was a problem in the opioid group. Postoperative dental pain--a comparative study of anti-inflammatory and analgesic agents. Campbell WI, et al. Ulster Hospital, Dundonald, Belfast. Ulster Med J 1991 Apr;60(1):39-43.

Dental Maxillo-Facial Surgery: Pentazocine Inferior to NSAID Ketamine: Ketamine and midazolam IV medication for conscious sedation in day-case maxillo-facial surgery, has been proven to be superior to pentazocine and midazolam concerning cardiovascular parameters and respiratory depression. In this DB PC study of 140 out-patients having dental surgery with local anaesthesia, ketamine(0.5 mg/kg)/midazolam was superior to pentazocine/midazolam postoperatively (vigilance). Analgesia-sedation for maxillo-facial surgery with midazolam-pentazocine and midazolam-ketamine. Clinical double-blind study of anxiety, analgesia, sedation and amnesia. Lipp M, et al. Johannes Gutenberg-Universitat Mainz. Anaesthe 1995 Aug;44(8):566-72.

Dental Surgery: Pentazocine Inferior to Pirprofen: In a DB PC study of 210 patients after oral surgery, pirprofen 200 and 400 mg both did better than pentazocin 100 mg for pain relief with the 400 mg dose more effective than the 200 mg dose (p< 0.05). The analgesia procured by the drug was perceptible after about 15 minutes. One of the 51 patients who received the 400 mg dose developed diarrhea, this being the only side effect observed. A study of the analgesic effects of pirprofen after oral surgery. Sperr W. Nouveau Presse Med 1982 Aug 28;11(33):2514-6.

Fracture Pain: Pentazocine Inferior to Indoprofen: In a 6-hour DB study of 60 patients with severe pain due to fractures, indoprofen 400 mg IV was superior to pentazocine 30 mg IV for pain relief. Placebo did worst. Indoprofen and pentazocine in post-traumatic pain. A double-blind, parallel-group comparative trial. Soave G, et al. J Int Med Res 1983;11(6):354-8.

General Practice Pain Patients: Narcotics Pentazocine and Dihydrocodeine Both Inferior to Acetaminophen; NSAID Floctafenine Best: In a DB PC study of 312 patients suffering from painful conditions, floctafenine was significantly superior in effect to pentazocine but not to the other three agents as far as doctor ratings were concerned; and superior to both pentazocine and dihydrocodeine in the opinion of patients. Fewer patients experienced side-effects on floctafenine than on the other four analgesics and this difference between floctafenine and pentazocine, and floctafenine and dihydrocodeine was statistically significant. A double-blind comparative clinical trial of floctafenine and four other analgesics conducted in general practice. Lomas DM, Gay J, Midha RN, Postlethwaite DL. J Int Med Res. 1976;4(3):179-82.

General Practice Pain Patients: Both Narcotics Inferior to NSAID Idarac and Slightly Inferior to Aspirin and Tylenol: In a DB study of 312 general practice patients suffering from painful conditions, NSAID floctafenine (Idarac) resulted in the most pain relief with the two narcotics dihydrocodeine and pentazocine doing worst and acetaminophen and aspirin intermediate although the superiority of acetaminophen and aspirin over the narcotics was not significant. Significantly fewer patients experienced side-effects on floctafenine than either narcotic. A double-blind comparative clinical trial of floctafenine and four other analgesics conducted in general practice. Lomas DM, et al. J Int Med Res 1976;4(3):179-82.

Surgical Post-Op Pain: Pentazocine No Better than NSAID Nefopam, But Had Many More Side-Effects: In a DB study of 50 patients undergoing surgery, nefopam did as well at relieving severe pain as pentazocine. In the nefopam group, 4/25 patients had side effects, vs. 10/25 in the pentazocine group (p< 0.05). The number of side effects was much greater in the pentazocine group (61) than the nefopam group (22) (p< 0.001). Double-blind clinical trial of nefopam in comparison with pentazocine in surgical patients. Pandit PN, et al. India. Br J Clin Pract 1989 Jun;43(6):209-14.

Surgery: Post-Op Pain: NSAID Flupirtine as Good as Two Narcotics with Fewer Side-Effects: In several DB studies of post-operative pain in 586 patients, flupirtine capsules 100 mg and suppositories 150 mg were as effective and acceptable as pentazocine and dihydrocodeine for the treatment of post-operative pain, but offered advantages in terms of fewer central nervous system side effects. It was at least as effective as the non-narcotics metamizole, paracetamol and naproxen. Flupirtine in the treatment of post-operative pain. Riethmuller-Winzen H. Homburg Degussa Pharma Gruppe, Frankfurt am Main, FRG. Postgrad Med J 1987;63 Suppl 3:61-5.

Surgery: Post-Neurosurgical Pain: Pentazocine No Better Than Non-Addictive Fluproquazone: In a DB PC study of 138 adults with post-neurosurgical pain, Comparison of the analgesic efficacy of the NSAID fluproquazone 200 mg, pentazocine 50 mg, and placebo against postoperative pain in neurosurgical patients, found both drugs equally effective. Hopfner R. Arzneimittelforschung. 1981;31(5a):927-9.

Surgery: Postsurgical Pain: Pentazocine No Better Than NSAID Propiram: In a DB study of adults with severe postsurgical pain, 50 mg propiram did as well at relieving pain as 50 mg pentazocine or 60 mg codeine with all better than placebo. (P< 0.05). Analgesic comparison of propiram fumarate with pentazocine, codeine, and placebo in postsurgical pain. Finch JS. J Clin Pharmacol 1980 Nov-Dec;20(11-12):689-92.