Ibuprofen and Flurbiprofen

Carborane Conjugates with Ibuprofen, Fenoprofen and Flurbiprofen: Synthesis, Characterization, COX Inhibition Potential and In Vitro Activity

The most effective anticancer drugs currently entail substantial and formidable side effects, and resistance of tumors to chemotherapeutic agents is a further challenge. Thus, the search for new anticancer drugs as well as novel therapeutic methods is still extremely important. Non-steroidal anti-inflammatory drugs (NSAIDs) can inhibit COX (cyclooxygenase), overexpressed in some tumors. Carboranes are emerging as promising pharmacophores. We have therefore combined both moieties in a single molecule to design drugs with a dual mode of action and enhanced effectiveness. The NSAIDs ibuprofen, flurbiprofen, and fenoprofen were connected with 1,2-dicarba-closo-dodecaborane(12) via methylene, ethylene or propylene spacers. Three sets of carborane-NSAID conjugates were synthesized and analyzed through multinuclear (1H, 11B, and 13C) NMR spectroscopy. Conjugates with methylene spacers exhibited the most potent COX inhibition potential, particularly conjugates with flurbiprofen and fenoprofen, displaying higher selectivity towards COX-1. Furthermore, conjugates with methylene and ethylene spacers were more efficient in suppressing the growth of human cancer cell lines than their propylene counterparts. The carborane-flurbiprofen conjugate with an ethylene spacer was the most efficient and selective toward the COX-2-negative cell line HCT116. Its mode of action was basically cytostatic with minor contribution of apoptotic cell death and dominance of cells trapped in the division process.

Modulation of nitric oxide effects by flurbiprofen enantiomers and nefopam and its relation to antinociception

We have examined the interactions of the analgesics, R- and S-flurbiprofen and nefopam, with nitric oxide (NO) in several experimental systems. Phenylephrine-precontracted rat aortic strips with intact endothelium were relaxed by R- and S-flurbiprofen and nefopam in a concentration-dependent manner. Removal of endothelium, inhibition of guanylate cyclase, inhibition of NO biosynthesis and inactivation of NO significantly reduced these relaxations. R- and S-flurbiprofen as well as nefopam enhanced the inhibition of platelet aggregation caused by rat peritoneal neutrophils or 3-morpholinosydnonimine. The antinociceptive effects of R- and S-flurbiprofen in the mouse writhing test as well as those of nefopam in the hot plate test were not significantly affected by administration of NO synthase inhibitors. We conclude that the increase in the biological activity of NO by R- and S-flurbiprofen and nefopam does not play a major role in the antinociceptive activity of the drugs, but might contribute to acute hypotension, a side-effect occasionally seen with flurbiprofen and nefopam.

Evaluation of the renal protective effect of misoprostol in elderly, osteoarthritic patients at risk for nonsteroidal anti-inflammatory drug-induced renal dysfunction

An age greater than 60 and diuretic use have been implicated as risk factors for nonsteroidal anti-inflammatory drug (NSAID)-induced decreases in renal function. Misoprostol, a prostaglandin E1 analog, was studied in nine elderly osteoarthritic patients at risk for NSAID-induced renal dysfunction to determine whether it could prevent NSAID-induced renal dysfunction. Subjects received ibuprofen 2400 mg/day and either misoprostol 800 mcg/day or placebo for 14 days in a randomized, double-blinded, crossover trial. Glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) studies using inulin and PAH plasma clearance, urinary prostaglandin E2 (PGE2) and protein excretion, and serum electrolytes were obtained at baseline, after the first dose, and on day 7 and 14 of each treatment period. Prostaglandin E2 excretion was significantly reduced after the first dose of ibuprofen and throughout the 14 days in both the misoprostol and placebo treatment groups. No statistically significant differences in GFR, ERPF, protein excretion, serum potassium, or serum sodium were detected between misoprostol and placebo treatment during the 14 days of ibuprofen treatment. However, a subset of two patients who exhibited a decrease of greater than 20% in GFR during placebo treatment, appeared to demonstrate an attenuation of this decline when treated with misoprostol. Effect of time, independent of treatment group, indicated that ERPF was significantly decreased from baseline after the first dose of ibuprofen (P < or = 0.05), whereas GFR was notably diminished from baseline on day 14 only (P < or = 0.05). Misoprostol does not influence GFR and ERPF in unselected subjects purportedly at risk for NSAID-induced renal dysfunction.(ABSTRACT TRUNCATED AT 250 WORDS)

Percutaneous absorption of flurbiprofen in the hairless rat measured in vivo using 19F magnetic resonance spectroscopy

The objective of this investigation was to develop a new methodology using 19F-magnetic resonance spectroscopy (MRS) to measure the in vivo percutaneous absorption of flurbiprofen through hairless rat skin. A 2% W/V flurbiprofen gel (Klucel HF, hydroxypropyl cellulose 1.5% to 2% W/V) containing isopropyl alcohol, water, and propylene glycol (55:35:10 v/v/v) was prepared. A 2-mg dose (100 mg of gel) was applied to the skin of the lower back of an anesthetized hairless rat, contained with a rubber o-ring, and occluded with a lexan plastic cover slip. The animal was placed on an MR surface coil (3.5-cm diameter tuned to 19F) and measurements taken continuously over approximately 3 h in 10-min intervals with a 2-tesla GE CSI nuclear magnetic resonance (NMR) spectrometer. One measures the disappearance of MR signal intensity per interval, which directly relates to the percent of drug disappearance over time, which in turn was converted to a flux value. The flux of flurbiprofen in vivo was found to be 95 +/- 22 micrograms/cm2/h. This is approximately four times greater than the flux of flurbiprofen through excised human skin reported by Akhter and Barry (22 +/- 14 micrograms/cm2/h). This new in vivo method measures drug disappearance and can be readily transferred to man. This method may be adapted to study other fluorine compounds or other nuclei with magnetic properties. It avoids exposure of a patient or animal to the radiation used in x-ray fluorescence methods or to 14C- or 3H-radiolabeled drugs.

The effect of flurbiprofen 0.03% eye drops on the blood aqueous barrier in extracapsular cataract extraction with IOL implantation

Preoperative and postoperative anterior chamber fluorophotometry were performed after intravenous administration of fluorescein sodium in patients undergoing extracapsular extraction and posterior chamber lens implantation. The topical application of aqueous flurbiprofen sodium 0.03% solution before and after surgery significantly decreased the surgery mediated disturbance of the blood aqueous barrier as compared to vehicle application (placebo controlled). In contrast to similar studies, cortical steroids were not given topically or systemically to either group of patients during the study. The present fluorophotometric results correlate well with slitlamp biomicroscopy of postoperative inflammation. The data of this study indicate that flurbiprofen ophthalmic solution is effective in protecting the blood aqueous barrier (BAB) in human eyes during cataract surgery and IOL implantation.

Pharmacokinetics and metabolism of 14C isobytylnaphtyl acetic acid in rat

After oral administration to rats, absorption of INAA was slow but complete. Plasma level curves reached a plateau for INAA as well as for the two metabolites, which were rapidly formed (MI and MII). The plateau concentration led to an increase of the apparent elimination half-life, which was short after i.v. administration due to the small volume of distribution and to the high rate of metabolism. In any case the half-life was independent of the dose and the pharmacokinetics of INAA remained linear from 1.5 to 15 mg/kg. The two rapidly formed plasma metabolites were eliminated more slowly than INAA. INAA and its metabolites were distributed only sparsely in all tissues under investigation, probably due to the high protein binding. Both routes of administration resulted in elimination of the radioactivity mainly by the urine. Besides the two main metabolites with known structures (MI and MII) small amounts of INAA and two additional metabolites were detected.

Metabolism of isobutylnaphthyl acetic acid in rats: determination of the chemical structures of metabolites

After oral and intravenous administration of radiolabelled isobutylnaphthyl acetic acid (INAA) to rats two metabolites were isolated from urine and plasma by HPLC. Field desorption, high resolution electron impact mass spectrometry as well as GC-MS after derivatization were used for structure elucidation and identification of the metabolites. The main biotransformation product in rat urine was found to be 5-(2'-hydroxy-2'-methyl-propyl)-1-naphthyl acetic acid (M1). The main metabolite in plasma was derived and was found to be 5-(2'-carboxypropyl)-1-naphthyl acetic acid (M2).

Excretion of flurbiprofen into breast milk

The extent of flurbiprofen's excretion into mature (postcolostrum) breast milk was evaluated in 10 healthy, nursing mothers after administration of a single 100-mg tablet. Samples of milk and blood were subsequently obtained over a 48-hour period and assayed for flurbiprofen by high-performance liquid chromatography. The average peak plasma flurbiprofen concentration, 15 micrograms/ml, occurred at 1.5 hours, and the harmonic mean half-life of the drug was 5.8 hours. The average peak milk concentration of flurbiprofen was 0.09 microgram/ml, and the maximum recovery of the dose in breast milk was only 0.07%.

An evaluation of the anti-inflammatory effect of flurbiprofen after cataract extraction

Thirty-eight patients requiring cataract extraction were randomly assigned to receive either flurbiprofen 100 mg twice daily in addition to routine postoperative therapy or the routine therapy alone. The trial was single blind with clinical assessments at postoperative days 1, 3, 7, 14, and 28. All measures of inflammatory response were significantly less in the group of patients receiving flurbiprofen, and in most cases the clinician's assessment as to which group each patient belonged to was correct. This trial suggests that flurbiprofen reduces inflammatory response in the eye in the first few days following cataract extraction and may therefore reduce the risk of severe and potentially disastrous reactions which sometimes occur.

Effects of chronic administration of doxorubicin on heart phospholipase A2 activity and in vitro synthesis and degradation of prostaglandins in rats

Male rats received doxorubicin (DXR) 2 mg/kg or phosphate buffered saline (PBS) weekly by the SC route for 13 weeks and were sacrificed at 14 and 19 weeks, one and six weeks, after the last dose, respectively. Heart phospholipase A2 activity in the 1000 X g supernatant was unchanged between DXR and PBS-treatment groups at both 14 and 19 weeks. In vitro heart microsomal syntheses of PGD2, PGE2, PGF2 alpha, and 6-keto-PGF1 alpha were significantly elevated in DXR-treated rats over controls at 14 weeks. In contrast, syntheses of TxB2, PGE2, and PGF2 alpha in DXR-treated rats were significantly depressed from controls at 19 weeks. In vitro heart metabolism of PGF2 alpha in the 100,000 X g supernatant fraction was significantly elevated in DXR treated rats over controls at 14 weeks, but unchanged from controls at 19 weeks. It was concluded from the findings of the present study that increased prostaglandin synthesis may play a role in the mediation of cardiac injury induced by doxorubicin.

Ibuprofen overdose: 126 cases

In this study of ibuprofen overdose, symptoms developed in 19% of patients (24 of 126)--in 7% of children (6 of 88) and in 47% of adults (18 of 38). Central nervous system depression, seizures, gastrointestinal disturbances, bradycardia, hypotension, apnea, abnormal renal functions, hematuria, nystagmus, and blurred vision were observed. No patients became symptomatic more than four hours after ingestion. There was no significant difference (P greater than .05) between symptomatic and asymptomatic adult groups in either total milligrams or milligram-per-kilogram amounts ingested by history. Pediatric patients who became symptomatic had a mean ingestion by history of 440 mg/kg; those who remained asymptomatic had a mean ingestion by history of 114 mg/kg (P less than .001). No patients ingesting less than 99 mg/kg by history developed any symptoms. Two children had seizures or apnea and one died. Ibuprofen occasionally may cause serious toxicity in overdose.

Rapid HPLC-determination of ibuprofen and flurbiprofen in plasma for therapeutic drug control and pharmacokinetic applications

Ibuprofen has wide applications in the treatment of rheumatoid arthritis and osteoarthroses as an effective non-steroidal antiinflammatory drug. The drug is still being investigated regarding its possible ability to reduce myocardial infarct size. The more potent biphenyl propionic analogue, flurbiprofen, has recently been introduced. Both drugs are strong inhibitors of cyclooxygenase. The specific HPLC-method described requires plasma samples of 100 microliter which are deproteinized and simultaneously extracted with acetonitrile containing either of the drugs as internal standard. Aliquots of 25 microliter of this primary extract were directly injected on a mu Bondapack C18 column. For elution was used a mixture of 60% methanol and 40% 50 mM phosphate buffer adjusted to pH 4.6. The detection limit (at 214 nm) for both drugs corresponded to plasma concentrations of about 0.2 micrograms X ml-1. The applicability of the method was demonstrated in a pharmacokinetic ibuprofen experiment in an adult person.

European experience with flurbiprofen. A new analgesic/anti-inflammatory agent

Numerous European clinical trials begun more than 12 years ago have clearly demonstrated flurbiprofen's safety and efficacy as an analgesic, anti-inflammatory, and antipyretic agent. In preclinical studies, flurbiprofen was at least as potent as indomethacin, and approximately 200 times more potent than aspirin. For patients with rheumatoid arthritis, a review of several trials found flurbiprofen often superior to aspirin and naproxen, and equivalent to indomethacin and ibuprofen in efficacy. Acetaminophen appeared no more effective than placebo for patients with rheumatoid arthritis. For patients with ankylosing spondylitis, flurbiprofen was also shown to be equivalent or superior to indomethacin and phenylbutazone. For patients with osteoarthritis of the peripheral joints, spine, hip, and knee, flurbiprofen was again found equal to ibuprofen, diclofenac, indomethacin, and naproxen. Side effects with flurbiprofen were few and predominantly related to the gastrointestinal tract.

A review of selected investigational nonsteroidal antiinflammatory drugs of the 1980s

We reviewed the literature on 7 investigational nonsteroidal antiinflammatory drugs (NSAIDs): fenbufen, flurbiprofen, tiaprofenic acid, diclofenac, fenclofenac, etodolac and proquazone. These drugs all appear to be at least as effective as currently marketed NSAIDs. Toxicity reported with these newer agents is similar to that seen with other drugs in this class, with gastrointestinal complaints being most commonly reported. The frequency of gastritis and the extent of gastrointestinal microbleeding are less than what occur with aspirin therapy. Fenclofenac may affect thyroid function tests, an effect not noted with other NSAIDs. Proquazone and fenclofenac may have some effect on immunologic function similar to those of slow-acting antirheumatic drugs. These drugs decrease immunoglobulins, rheumatoid factor and C-reactive protein. The place for these drugs in the management of rheumatic diseases has yet to be defined. They may prove to be more beneficial than currently marketed drugs for some patients.

Double-blind trial of flurbiprofen and phenylbutazone in acute gouty arthritis

Flurbiprofen has been compared with phenylbutazone in a double-blind study involving 33 patients with acute gout. Patients received either flurbiprofen 400 mg daily for 48 h followed by 200 mg daily, or phenylbutazone 800 mg daily for 48 h followed by 400 mg daily. The drugs were of comparable efficacy, while side-effects were uncommon and relatively mild. Flurbiprofen appears to be a satisfactory alternative to phenylbutazone in the management of acute gouty arthritis.

Effects of nonsteroidal anti-inflammatory drugs on prostaglandins and renal function

In the past 15 years, there has been an explosion in the number of nonsteroidal anti-inflammatory drugs on the market. Along with this explosion have come increasing reports of the physiologic and pathologic changes seen in the kidneys. This report reviews the effects of prostaglandins on the kidney and the physiologic changes that result when prostaglandin synthesis is blocked. The world literature on renal complications of nonsteroidal anti-inflammatory drugs is reviewed and 274 cases of acute renal disease associated with their use are reported. The following cases are described: nephrotic syndrome (34); acute interstitial nephritis (51); acute tubular necrosis (29); papillary necrosis (53); poor perfusion with renal failure (40); acute glomerulitis or vasculitis (13); and unspecified renal failure (102). Fenoprofen appeared to be more nephrotoxic than other nonsteroidal anti-inflammatory drugs and resulted in multiple renal lesions in the same patient.

Ibuprofen, pharmacokinetics and pharmacodynamics in the isolated rabbit heart

Myocardial pharmacokinetics and dynamic effects of the non-steroidal antiinflammatory drug ibuprofen were studied in isolated, spontaneously beating and retrogradely perfused rabbit hearts. Both myocardial uptake and disposition of ibuprofen showed two-compartment characteristics, which possibly reflects extracellular and intracellular binding sites. Initial and terminal kinetic half-lives were about 0.6 and 13.4 min., respectively. Vd beta was about 82 ml/g myocardial tissue. Stepwise increased ibuprofen concentrations from 30 to 160 micrograms/ml in the Krebs-Henseleit perfusion liquid produced a progressive increase in coronary flowrate up to 178%, which then decreased somewhat at higher concentrations. Preliminary observations showed a direct relaxing effect on PGF-2 alpha produced contractions in coronary vasculature. Oxygen consumption increased simultaneously to 143% at 160 micrograms/ml and then decreased. Myocardial contractility (measured by amplitude and rate of contraction) decreased progressively to about 55% at concentrations from 60-160 micrograms/ml and further to 20% at 580 micrograms/ml. Myocardial efficiency expressed as the ratio of contraction rate to oxygen consumption decreased to about 0.2. Heart beat frequency decreased simultaneously to 73%. The electrocardiographic PQ and QRS intervals increased to 143 and 139%, respectively, whereas the QT interval did not increase significantly. Asystolia occurred in some cases at ibuprofen concentrations of 580 micrograms/ml. The findings suggest that ibuprofen at therapeutic concentrations may possibly produce some coronary vasodilation accompanied by a slight negative inotropic effect. Interactions with other cardioactive drugs seem possible. The drug may cause direct cardiotoxic effects at supratherapeutic concentrations.

Comparative evaluation of antipyretic activity of ibuprofen and aspirin in children with pyrexia of varied aetiology

The antipyretic activity of ibuprofen and aspirin was compared in sixteen children with pyrexia due to upper respiratory tract infection and in twelve with fever due to other causes. All 28 children received ibuprofen (7 mg/kg of body-weight) and aspirin (15 mg/kg of body-weight) in a single dose on 2 consecutive days in a crossover manner. Rectal temperature was recorded prior to and at regular intervals up to 8 hours after drug administration. Analysis of the results indicate that ibuprofen and aspirin effectively lower temperature and the two drugs are comparable in their antipyretic activity. In conclusion, significant antipyretic activity, good tolerance profile and availability in syrup form make ibuprofen a useful substitute for aspirin in children with fever.

Review of ibuprofen for osteoarthritis

Pain is the predominant reason for seeking treatment in patients with osteoarthritis. Management is multifactorial, involving psychological, physical, pharmaceutical, and sometimes surgical measures. Nonsteroidal anti-inflammatory agents play a valuable role in the overall treatment program. A review of 28 clinical trials involving ibuprofen for osteoarthritis shows sometimes conflicting results in efficacy, often because of inadequacies in study design or dosage. In fact, 17 of these 28 studies employed doses of less than 1,600 mg/day. Nonetheless, several trends are clear. Ibuprofen at a dose of over 1,200 mg daily was superior to placebo and at doses of 1,200 to 1,800 mg/day was as effective or more effective than 3,200 to 3,600 mg/day of aspirin or 4,500 mg/day of aspirin plus acetaminophen. In trials with a wide variety of other nonsteroidal anti-inflammatory drugs, ibuprofen was often as effective as the comparison agent. Tolerability was consistently excellent with ibuprofen, and adverse reactions were few.

Effect of ibuprofen on doxorubicin toxicity in mice

This study examines the effect of ibuprofen on the toxicity produced in mice by the anticancer drug, doxorubicin. Ibuprofen solution made in 0.02% sodium carbonate, was administered subcutaneously in doses ranging from 10 to 40 mg/kg/day. Sodium carbonate served as a vehicle control and saline was used as a reference control. Treatment with saline, sodium carbonate, or a specific dose of ibuprofen began two days before administration of a single intraperitoneal dose of doxorubicin 17, 20 or 25 mg/kg and then continued for the next thirty days. Mortality was followed for thirty days. The analysis of the data by the Litchfield and Wilcoxon method revealed that there was neither a difference in doxorubicin LD50 values nor in the potency ratios between saline and any dose of ibuprofen treatment. Treatments with sodium carbonate and ibuprofen at 30 mg/kg/day offered slight protection over saline treatment, but it was not statistically significant. All mice, regardless of treatment, receiving doxorubicin showed significant weight loss. It appears that ibuprofen offers little protection against doxorubicin toxicity under these circumstances.

Inferior vena cava replacement: the role of antiplatelet therapy

To evaluate the effect of ibuprofen on early thrombus formation following inferior vena cava (IVC) replacement, a 4-cm segment of IVC was replaced with a 5-cm (10-mm-i.d.) segment of reinforced polytetrafluoroethylene (PTFE) graft in 12 dogs. Autologous platelets and canine fibrinogen were labeled with 111In and 125I, respectively, and injected into each animal 24 hr prior to vena cava replacement. Six dogs served as controls and six were treated with 12.5 mg/kg ibuprofen intravenously 1 hr preoperatively. All dogs were heparinized with 100 U/kg intravenous heparin prior to crossclamping the IVC: heparin was not reversed at the end of the procedure. Three hours after normal circulation was restored, the grafts were removed and counts of radioactivity made. All grafts were patent. The mean platelet count for the control group was 12.8 X 10(6)/mm2, while in the grafts from the treated group it was 0.960 X 10(6)/mm2. The decreased platelet deposition was significant in all graft segments (P less than 0.01). Fibrin deposition was reduced from 3.38 micrograms/mm2 to 0.25 micrograms/mm2 (P less than 0.01) by ibuprofen. Although fibrin and red blood cells are the major constituents of venous thrombi, platelet aggregation appears to play an important role if prosthetic material is implanted into the venous system. Ibuprofen not only reduced platelet deposition by 13.5-fold, but also reduced fibrin deposition by 13.5-fold. The ratio of platelets to fibrin in control and treated animals was similar (3.84 and 3.79, respectively). These data suggest that antiplatelet medication combined with heparin therapy might decrease early thrombus formation in venous prostheses.

Acute poisoning with ibuprofen

1 Seventy five cases of ibuprofen overdose were recorded during a two year survey. 2 Details of the symptoms, treatment and the eventual outcome are known for 64% of the cases. The majority of the patients had no symptoms or only mild symptoms such as nausea or vomiting. 3 In the three cases where more serious symptoms were reported, the role of ibuprofen was not certain. 4 Laboratory analyses available for 13 cases demonstrate that plasma ibuprofen concentrations of up to 704 mg/l could be associated with no symptoms. 5 The data suggest that ibuprofen is of low toxicity in acute overdose and that therapy used should be supportive only.

The binding of ibuprofen to plasma proteins

The binding of ibuprofen to human serum albumin, normal plasma and plasma obtained from rheumatoid arthritic patients was studied using the method of ultracentrifugation. It was found that ibuprofen is more strongly bound to normal plasma than to human serum albumin although this result is probably explained by fatty acid contamination of the human serum albumin. The fraction of ibuprofen not bound to normal plasma rose significantly from a value of 0.0128 at an ibuprofen concentration of 2 mg X l-1 to 0.0155 at a concentration of 50 mg X l-1. Ibuprofen was less strongly bound to rheumatoid plasma than to normal plasma but this difference can be accounted for by the difference in albumin concentration between the two plasmas. It was found that salicylic acid can displace ibuprofen from protein binding sites, in vitro, and that this is the probable cause of the pharmacokinetic interaction between the two drugs.