Fluoxetine Potentiate the Analgesic Effect of Diclofenac in Male Mice

Selman Mohammed Selman
Authors Emails are requested on demand or by logging in
Keywords : diclofenac, fluoxetine, tail-flick test, mice.
Medical Journal of Babylon  14:3 , 2018 doi:1812-156X-14-3
Published :05 January 2018

Abstract

Fluoxetine is a selective serotonin re-uptake inhibitors (SSRI) drug, which is the most widely used in the treatment of depression. The aims of this study were to evaluate the analgesic effects of fluoxetine, and the analgesic effect of combination of fluoxetine and diclofenac in model of thermal pain in male mice. Mice were divided into four groups, six in each. Group 1 received normal saline. Group 2received diclofenac. Group 3 received fluoxetine. Group 4 received fluoxetine before the administration of diclofenac. Evaluation of the analgesic action of the drug was achieved by the tail flick test. Tail-flick latency significantly increased (P < 0.05) in the group 2 in the 2 time intervals as compared to control group. In the group 3, there were no significant changes (P > 0.05) in the tail-flick latency after 30 min as compared to corresponding time of control group, while it significantly increased (P < 0.05) after 60 min as compared to corresponding time of control group. In the group 4caused significant increase (P < 0.05) in the time of tail-flick latency after 60 min as compared to corresponding time of diclofenac group and fluoxetine group. In this study, combination of low dose diclofenac with fluoxetine caused a significant prolongation of tail-flick latency proposing additive antinociceptive effect. Thus, combination of diclofenac with fluoxetine hypothetically reduce the dose requirement and adverse effects for each drug.. Further clinical studies are needed to prove these effects.

Introduction

Pain which associated with tissue damage and inflammation possibly results from stimulation of the fibers of the pain and enhanced pain sensitivity (hyperalgesia), which is a part of increased excitability of the neurons in spinal cord(central sensitization) [1]. Cytokines such as IL-1, IL-8 and TNF? have an important role in producing the pain of inflammation. These mediators release prostaglandins and perhaps other agents such as substance P that produce hyperalgesia. Intramuscular or sub-cutaneous injections of PGF2 or PGE2 cause severe local pain. Also, prosta-glandins can produce vascular pain and headache when infused intravenously. Prostaglandins sensitize pain receptors to chemical and mechanical stimulation due to the ability of prostaglandins to reducing of the threshold of the polymodalno-ciceptors of fibers type C [2]. NSAIDs interfere with the prostaglandins biosynthesis by inhibition fatty acid cyclooxygenase-1 (COX-1) which convers arachidonic acid into the PGG2, and PGH2 [3]. Diclofenac is an inhibitor of COX-1 and its potency greater than that of several agents of NSAIDs such as naproxen, or indomethacin [4]. The drug is rapidly absorbed after oral dose, and the peak plasma concentrations are reached after 2 to 3 hours. Administration of diclofenac with food reduce the rate of absorption [5]. Only 50% of the drug is available systematically because it face first-pass effect. It is bound to plasma protein extensively (99%) [6,7]. The duration of the therapeutic effect of the drug is longer than the half-life due to the accumulation of the drug in the synovial fluid after intramuscular or oral administration. Metabolism of diclofenac occurs in the liver by a cytochrome P450 isozyme after sulfation and glucuronidation, and the metabolites are excreted in bile and urine [8,9]. Fluoxetineis a selective serotonin re-uptake inhibitors (SSRI) drug, which is the most widely used in the treatment of depression [10]. It is also used to treat another type of anxiety disorder called obsessive-compulsive disorder. It has less anticholinergic side effects than those of tricyclic antidepressants (TCAs), [11] in addition to that, it causes no cheese reactions which occurs in monoamines inhibitors (MAOIs) [12]. Fluoxetine is well absorbed after oral administration, and the half-life is 24-96 hours. The drug needs 2-3 weeks to elicit its therapeutic effects [13]. Many studies proved that antidepressant drugs have analgesic effect specially SSRIs [14] fluoxetine is able to reverse or prevent hyperalgesia in animal model of pain [15]. Pain of diabetic neuropathy, migraine [16] and perhaps rheumatoid arthritis response to antidepressants [17]. The aims of this study were to evaluate the analgesic effects of fluoxetine, and the analgesic effect of combination of fluoxetine and diclofenac in model of thermal pain in mice.

Materials and methods

Animals:
Twenty fourmale adult  mice(25- 30 g) were enrolled in this experiment. The animals were retainedin the Animal House of College of Medicine/University of Babylon, 12 hours light-dark cycles and the temperature was controlled on 25 °C. Tap water with  standard diet ad libitum were provided. After 2 weeks for accommodation, the micewere divided randomly into four groups, each group had six mice.
Group 1 (control group): The animals received normal saline equal to the volume of the diclofenac which administered intra-peritineally. 
Group 2: In this group, each mouse received diclofenac, 3 mg/kg, intra-peritoneally.
Group 3: In this group, each mouse received 10 mg/kg of fluoxetine, orally.
Group 4: In this group, each mouse received 10 mg/kg of fluoxetine , orally thirty min before the administration of diclofenac, 3 mg/kg, intraperitoneally.

Evaluation of antinociceptive effect of the drugs
Evaluation of antinociceptive action of drugs was achieved  by the tail flick test [18]. Each mouse was restrained by suitable container which fixed on the water bath allowing the last 2 cm of the tail immersed in the heated water (50 ± 0.2 °C). Measurement of the time to tail twistingor flicking i.e. the reaction considered  as the tail-flick latency.
Each mouse was tested at time intervals 0 min, 30 min, and 60 min after the drug administrations. In addition to that, each mouse was tested three trials in each interval separated by 3-5 min. For each mouse, the mean of 3 measurements was considered as the time of tail-flick latency. In each trial, the cut-off time of 3 min to prevent tissue injury.
Drugs
Fluoxetine capsule, 20 mg (Actavis, Irland) 20 was dissolved in 10 ml of isotonic saline (0.9% NaCl) and the final product was 2 mg/ml. Diclofenac sodium ampule 75/2ml (Olfen-75, Acino, Switzerland)  was used in this experiment. 
Statistical analysis
     Results of this study were expressed as mean ± standard error mean (SEM) and one-way ANOVA was used for comparison between means. Value was considered as a statistically significant when the P value< 0.05.Statistical analysis was done by using SPSS (version 18).




Results

1- Control group In the control group, there were no significant differences in the time of tail-flick latency after 30 min as compared to the tail-flick latency after 60 min (P > 0.05). (Tables 1 and 2) 2- Effects of diclofenac Tail-flick latency significantly increased (P<0.05) in the group 2 (received diclofenac 3mg/kg) in the 2 time intervals as compared to control group. Diclofenac produced significant differences in the time of the tail-flick latency after 30 min as compared to the tail flick latency at 0 min but there were no significant changes in the time of the tail-flick latency (P > 0.05) after 60 min as compared to the tail-flick latency after 30 min. The time of the tail-flick latency significantly increased after 30 min as compared to corresponding time of fluoxetine (P<0.05), while there were no significant differences in the time of tail-flick latency after 60 min as compared to corresponding time of fluoxetine (P>0.05) (Tables 1 and 2). 3- Effects of fluoxetine In the group 3 (received fluoxetine, 10 mg/kg), there were no significant changes in the time of tail-flick latency after 30 min as compared to corresponding time of control group (P>0.05), while it significantly increased (P<0.05) after 60 min as compared to corresponding time of control group. Fluoxetine produced no significant changes in the time of the tail-flick latency after 30 min as compared to the time of the tail-flick latency at 0 min but it significantly increased after 60 min as compared to tail-flick latency after 30 min (P < 0.05). (Tables 1 and 2) 4- Effects of combination of dilclofenac and fluoxetine In the group 4 (received diclofenac, 3mg/kg and fluoxetine, 10 mg/kg), the time of the tail-flick latency significantly increased after 30 min as compared to the corresponding times of control group and fluoxetine group (P<0.05), while there were no significant changes (P > 0.05) as compared to the corresponding time of diclofenac group. Diclofenac and fluoxetine caused significant changes in the time of the tail-flick latency after 30 min as compared to the tail-flick latency in 0 min. In addition, it significantly increased after 60 min as compared to tail-flick latency after 30 min (P < 0.05). Combination of diclofenac and fluoxetine caused significant increase (P < 0.05) in the time of the tail-flick latency after 60 min as compared to corresponding time of diclofenac group and fluoxetine group. (Tables-1&2).

Discussions

This study showed that the antinociceptive action of low dose Diclofenac (3mg/kg) against thermal pain in mice was obvious after intraperitoneal injection, expressed as prolongation in the tail-flick latency after 30 min, then this effect increased after 60 min. Diclofenacis classified as a NSAID which can inhibit the actions of both types of cyclooxygenase enzymes (cyclooxygenase -1 and cyclooxygenase-2). These agents are useful in the management of inflammatory disorders and pain [19]. Non-steroidal anti-inflammatory drugs are widely used because these drugs relieve inflammation and pain and the patients return to usual functions [20]. Data of this study revealed that after 60 min of oral dose of 10 mg/kg, fluoxetine caused anti-nociceptive effect. This result is in agreement with the several clinical and experimental researches have reported the analgesic activity of antideprassants [21,22]. The major effect of anti-depressants is inhibition of re-uptake of monoamines [23]. Several reports have linked the actions of fluoxetine to the serotonergic pathway [24-26]. Many brain areas supplies periaque-ductal grey area and supposed it is a gateway in control the pain. Periaque-ductal grey area stimulates the nucleus raphemagnusin the spinal cord, that connected by synapses with dorsal horn interneurons. At these synaptic connections, the main neurotransmitter is serotonin and the tract from nucleus raphe magnusto the substantiagelatinosa which is located in the dorsal horn [27]. Stimulation of this path inhibits nociceptive pathway. At the dorsal horn of spinal cord, 5-HT3 receptors mediate the analgesic action [28]. SSRIs inhibit the serotonin reuptake leading to increase the amount of serotonin in the synaptic cleft, extension of this effect on the serotonergic pathway in the spinal cord may explain the antinociceptive action of SSRI drugs. Recently, many researchers reported that naloxone can antagonized fluoxetine-induced antinociceptive action [16,29]. Therefore it likely that fluoxetine exhibits its actions via opioid pathways including the µ receptors. In this study, combination of low dose diclofenac with fluoxetine caused a significant prolongation of tail-flick latencyproposing additive antinociceptive effect. Therefore, fluoxetine significantly potentiate the analgesic action of diclofenac in pain model when given together. Many agents which are used for treatment other than pain, maybe have antinociceptive effects in specific situations, these agents called Co-analgesics [30]. This combination enhances the analgesic effect of the agent without increasing the dose of the analgesic agent. Thus, it can moderatethe occurrence of unwanted side effects [31]. It is a great value in treatment of the pain, when a combination of two types of agents at doses less than therapeutic doses [32]. Thus, combination of diclofenac with fluoxetine hypothetically reduce the dose requirementand adverse effects for each drug. Further clinical studies are needed to prove these effects.

References

1- Konttinen YT, Kemppinen P, Segerberg M, Hukkanen M, Rees R, Santavirta S, Sorsa T, Pertovaara A, Polak JM. Peripheral and spinal neural mechanisms in arthritis, withj particular reference to treatment of inflammation and pain. Arthritis Rheum; 1994; 37: 965-982.
2- Gebhart GF, McCormack KJ. Neuronal plasticity. Implication for pain therapy. Drugs. 1994; 47 (suppl 5): 1-47.
3- Vane JR, Bakhle YS, Botting RM. Cyclooxygenase 1 and 2. Annu Rev Pharmacol. 1998; 38: 97-120.
4- Lewis AJ, Furst DW. Nonsteroidal Anti-Inflammatory Druds: Mechanism and Clinicle Use. Marcel Dekker, New York, 1987.
5- Willis, JV, Kendall MJ, Jack DB.A study of the effect of aspirin on the pharmacokinetics of oral and intra-venous diclofenac sodium. Eur J Clin Pharmacol., 1980; 18: 415.
6- Zhengyin Y, Jian L, Norman H, Gary WC, Yanming D, Hua Z. Detection of a noval reactive metabolite of diclofenac: evidence for CYP2C (-mediated bio-activation via arene oxides. Drug Metab and Dispos, 2005; 33(6): 706-713
7- Nicole AK, Walter H, Francis M, Manfred K, Paul RG Predicting plasma protein binding of drugs: a new approach. BiochemPharmacol, 2002; 64 (9); 1355-1374.
8- Tang W. The metabolism of diclofenac-enzymology and toxicology perspectives. Curr Drug Metab, 2003 Aug; 4(4): 319-329.
9- Andrade SE, Martinez C, Walker AM. Comparative safety evaluation of non- narcotic analgesics. J Clin Epidemiol. 1998; 51:1357-1365.
10- Song F, Freemantle N, Sheldon TA. Selective serotonin reuptake inhibitors: meta-analysis of efficacy and accept-ability. Br Med J, 1993; 683-687.
11- Bech P, Cialdella P, Haugh MC, Birkett MA, Hours A, Boissel JP, Tollefson GD. Meta-analysis of randomised controlled trials of fluoxetine v. placebo and tricyclic antidepressants in the short-term treatment of major depression. British Journal of Psychiatry. 2000;176:421–428.
12- Wong DT, Bymaster FP, Engleman EA. Minireview: Prozac (Fluoxetine, Lilly 110140), the first selective selective serotonin uptake inhibitor and an antidepressant drug: twenty years since its first publication. Life Sci. 1995; 57: 411–441.
13- Wilde MI, Benfield P. Fluoxetine: A pharmacoeconomic review of its use in depression. Pharmaco Economics. 1998; 13: 543–561.
14- Jung AC, Stagier T, Sullivan M. The efficacy of selective serotonin reuptake inhibitors for the management of chronic pain. J Gen Inter Med, 1997; 12: 384-389
15- Begovic A, Zulic I, Becic F. Testing of analgesic effect of fluoxetine. Bosn J Basic Med Sci, 2004; 4:79-81
16- Singh VP, Jain NK, Kulkarni SK. On the antinociceptive effect of fluoxetine, a selective serotonin reuptake inhibitor. Brain Res, 2001; 915: 218-226.
17- Scott WAM. The relief the pain with an antidepressant in arthritis. Prac, 1969; 202: 802-807
18- D Amour FE, Smith DL. A method for determining loss of pain sensation. J PharmacolExpTher. 1941; 72: 74-79.
19- Telliment JP, Albengres E. The pharmacologic basis of pain treatment. Therapie, 2001; 56(6); 687-696.
20- L, Approaches to nonsteroidal anti-inflammatory drug use in the high-risk patient. Gastroenterology 2001; 120: (3): 594-606.
21- Magni G. The use of antidepressants in treatment of chronic pain. Drugs, 1991; 42: 730-748.
22- Ventafridda V, Bianchl M, Ripamonti C, Sacerdote p, De Conno F, Zecca E. Studies on the effects of antidepressant drugs on the antinociceptive action of morphine and on plasma morphine in rat and man. Pain, 1990; 43: 155-162.
23- Hyttel J. Pharmacological characteri-zation of selective serotonin reuptake inhibitors (SSRIs). Int Clin Psych pharmacol, 1992; 326: 1250-1256.
24- Glauman SR, Proudfit HK, Anderson EG. Reversal of the antinoceceptive effect effect of intrathecally administered serotonin in the rat by a selective 5-HT3 receptor antagonists. Neuroscience Letters, 1988; 95(1-3): 313-317.
25- Glauman SR, Proudfit HK, Anderson EG. 5-HT3 receptors modulate spinal nociceptive reflexes. Brain Res., 1990; 510 (1): 12-16.
26- Bardin L, Schmidt J, AllouiA, Eschalier A. Effect of intrathecal administration of serotonin in chronic pain model in rats. European Journal of Pharmacology, 2000; 409(1): 37-43.
27- Richelson E. Where are all the novel antidepressant? Current Opinion in Investigational Drugs, 2001; 2(2): 256-258.
28- Sasaki M, Ishizaki K, Obata H, Goto T. Effects of 5-HT2 and 5-HT3 receptors on the modulation of nociceptive trans-mission in rat spinal cord according to the formalin test. European Journal of Pharmacology, 2001; 424(1): 45-52.
29- Rafleian-KopaeiM, Sewell RDE. Newer antidepressants: algesia and relative monoamines reuptake inhibitory potency. J Pharm pharmacol 1994; 46: 1088.
30- Lamont LA, Tranquilli WJ, Mathews KA. Adjunctive analgesic therapy. Vet Clin North Am Anim Prac, 2000; 30(4): 805-813
31- Hewitt DJ. The use of NMDA-receptor antagonists in the treatment of chronic pain. Clin J Pain, 2000; 16(2 Suppl): S73-79
32- Lange H, Krank P, Steffen P, Steinfeld T, Wulf H, Eberhart LHJ. Combined analgesics for postoperative pain therapy. Review of effective and side-effects. Der Anaesthsist, 2007; 56(10): 1001-1016.


The complete article is available as a PDF File that is freely accessible. The fully formatted HTML version can be viewed as HTML Page.

Medical Journal of Babylon

volume 14 : 3

Share |

Viewing Options

Abstract
Download Abstract File
( 5 KB )

Related literature

Cited By
Google Blog Search
Other Articles by authors

Related articles/pages

On Google
On Google Scholar
On UOBabylon Rep

User Interaction

269  Users accessed this article in 1 year past
Last Access was at
14/08/2018 04:57:09