Bifen

In children ingestion of more than 400mg/kg may cause symptoms. In adults the dose response effect is less clear cut. The half-life in overdose is 1.5-3 hours.

Symptoms

Most patients who have ingested clinically important amounts of NSAIDs will develop no more than nausea, vomiting, epigastric pain, or more rarely diarrhoea. Tinnitus, headache and gastrointestinal bleeding are also possible. In more serious poisoning, toxicity is seen in the central nervous system, manifesting as vertigo, headache, respiratory depression, dyspnoea, drowsiness, occasionally excitation and disorientation or coma. Occasionally patents develop convulsions. In serious poisoning, hypotension, hyperkalaemia, and metabolic acidosis may occur and the prothrombin time / INR may be prolonged, probably due to interference with the actions of circulating clotting factors. Acute renal failure and liver damage may occur. Exacerbation of asthma is possible in asthmatics.

Management

Should be symptomatic and supportive and include maintenance of a clear airway and monitoring of cardiac and vital signs until stable. Consider oral administration of activated charcoal if the patient presents within 1 hour of ingestion of a potentially toxic amount. If frequent or prolonged, convulsions should be treated with intravenous diazepam or lorazepam. Give bronchodilators for asthma.

In children ingestion of more than 400mg/kg may cause symptoms. In adults the dose response effect is less clear cut. The half-life in overdose is 1.5-3 hours.

Symptoms:

Most patients who have ingested clinically important amounts of NSAIDs will develop no more than nausea, vomiting, epigastric pain, or more rarely diarrhoea. Tinnitus, headache and gastrointestinal bleeding are also possible. In more serious poisoning, toxicity is seen in the central nervous system, manifesting as drowsiness, occasionally excitation and disorientation or coma. Occasionally patients develop convulsions. In serious poisoning metabolic acidosis may occur and the prothrombin time/INR may be prolonged, probably due to interference with the actions of circulating clotting factors. Acute renal failure and liver damage may occur. Exacerbation of asthma is possible in asthmatics.

Management:

Management should be symptomatic and supportive and include the maintenance of a clear airway and monitoring of cardiac and vital signs until stable. Consider oral administration of activated charcoal if the patient presents within 1 hour of ingestion of a potentially toxic amount. If frequent or prolonged, convulsions should be treated with intravenous diazepam or lorazepam. Give bronchodilators for asthma.

In case of overdose, get medical help or contact a Poison Control Center right away.

Toxicity

Signs and symptoms of toxicity have generally not been observed at doses below 100 mg/kg in children or adults. However, supportive care may be needed in some cases. Children have been observed to manifest signs and symptoms of toxicity after ingestion of 400 mg/kg or greater.

Symptoms

Most patients who have ingested significant amounts of ibuprofen will manifest symptoms within 4 to 6 hours.

The most frequently reported symptoms of overdose include nausea, vomiting, abdominal pain, lethargy and drowsiness. Central nervous system (CNS) effects include headache, tinnitus, dizziness, convulsion, and loss of consciousness. Nystagmus, metabolic acidosis, hypothermia, renal effects, gastrointestinal bleeding, coma, apnoea, diarrhoea and depression of the CNS and respiratory system have also been rarely reported. Disorientation, excitation, fainting and cardiovascular toxicity, including hypotension, bradycardia and tachycardia have been reported. In cases of significant overdose, renal failure and liver damage are possible. Large overdoses are generally well tolerated when no other drugs are being taken.

Therapeutic measures

Patients should be treated symptomatically as required. Within one hour of ingestion of a potentially toxic amount, activated charcoal should be considered. Alternatively, in adults, gastric lavage should be considered within one hour of ingestion of a potentially life-threatening overdose.

Good urine output should be ensured.

Renal and liver function should be closely monitored.

Patients should be observed for at least four hours after ingestion of potentially toxic amounts.

Frequent or prolonged convulsions should be treated with intravenous diazepam. Other measures may be indicated by the patient's clinical condition.

Symptoms following acute NSAID overdosages have been typically limited to lethargy, drowsiness, nausea, vomiting, and epigastric pain, which have been generally reversible with supportive care. Gastrointestinal bleeding has occurred. Hypertension, acute renal failure, respiratory depression, and coma have occurred, but were rare.

Manage patients with symptomatic and supportive care following an NSAID overdosage. There are no specific antidotes. Forced diuresis, alkalinization of urine, hemodialysis, or hemoperfusion may not be useful due to high protein binding.

For additional information about overdosage treatment contact a poison control center at 1-800-222-1222.

No case of overdose has been reported with intravenous ibuprofen in preterm newborn infants.

However, overdose has been described in infants and children administered oral ibuprofen: CNS depression, seizures, gastrointestinal disturbances, bradycardia, hypotension, apnoea, abnormal renal function, haematuria have been observed.

Massive overdose (up to more than 1000 mg/kg) has been reported to induce coma, metabolic acidosis, and transient renal failure. All patients recovered with conventional treatment. Only one recorded death has been published: after an overdose of 469 mg/kg, a 16-month old child developed an apnoeic episode with seizures and a fatal aspiration pneumonia.

The management of ibuprofen overdose is primarily supportive.

The following signs and symptoms have occurred in individuals (not necessarily in premature infants) following an overdose of oral ibuprofen: breathing difficulties, coma, drowsiness, irregular heartbeat, kidney failure, low blood pressure, seizures, and vomiting. There are no specific measures to treat acute overdosage with Bifen. The patient should be followed for several days because gastrointestinal ulceration and hemorrhage may occur.

Pharmacotherapeutic group: Propionic acid derivatives.

ATC Code: M01AE

Bifen is a phenylpropionic acid derivative NSAID that has demonstrated its efficacy by inhibition of prostaglandin synthesis. In humans, Bifen reduces inflammatory pain, swelling and fever. Furthermore, Bifen reversibly inhibits platelet aggregation.

Experimental data suggest that Bifen may competitively inhibit the effect of low dose aspirin (acetylsalicylic acid) on platelet aggregation when they are dosed concomitantly. Some pharmacodynamics studies show that when single doses of Bifen 400mg were taken within 30 min after immediate release aspirin (acetylsalicylic acid) dosing (81 mg), a decreased effect of aspirin (acetylsalicylic acid) on the formation of thromboxane or platelet aggregation occurred. Although there are uncertainties regarding extrapolation of these data to the clinical situation, the possibility that regular, long-term use of Bifen may reduce the cardioprotective effect of low-dose aspirin (acetylsalicylic acid) cannot be excluded. No clinically relevant effect is considered to be likely for occasional Bifen use.

ATC Code: M01AE01

Ibuprofen is a propionic acid derivative NSAID that has demonstrated its efficacy by inhibition of prostaglandin synthesis. In humans, ibuprofen reduces inflammatory pain, swellings and fever. Furthermore, ibuprofen reversibly inhibits platelet aggregation.

Experimental data suggest that ibuprofen may competitively inhibit the effect of low dose aspirin (acetylsalicylic acid) on platelet aggregation when they are dosed concomitantly. Some pharmacodynamics studies show that when single doses of ibuprofen 400mg were taken within 8 h before or within 30 min after immediate release aspirin dosing (81mg), a decreased effect of (acetylsalicylic acid) on the formation of thromboxane or platelet aggregation occurred. Although there are uncertainties regarding extrapolation of these data to the clinical situation, the possibility that regular, long-term use of ibuprofen may reduce the cardioprotective effect of low-dose acetylsalicylic acid cannot be excluded. No clinically relevant effect is considered to be likely for occasional ibuprofen use.

Pharmacotherapeutic classification: Anti-inflammatory and antirheumatic products, nonsteroidal; propionic acid derivatives.

ATC code: M01AE01

Ibuprofen is a propionic acid derivative with analgesic, anti-inflammatory and antipyretic activity. The drug's therapeutic effect as an NSAID is thought to result from its inhibitory effect on the enzyme cyclo-oxygenase, which results in a marked reduction in prostaglandin synthesis.

Experimental data suggest that ibuprofen may competitively inhibit the effect of low dose aspirin on platelet aggregation when they are dosed concomitantly. Some pharmacodynamic studies show that when single doses of ibuprofen 400mg were taken within 8 hours before or within 30 minutes after immediate release aspirin dosing (81mg), a decreased effect of aspirin on the formation of thromboxane or platelet aggregation occurred. Although there are uncertainties regarding extrapolation of these data to the clinical situation, the possibility that regular, long-term use of ibuprofen may reduce the cardioprotective effect of low-dose acetylsalicylic acid cannot be excluded. No clinically relevant effect is considered to be likely for occasional ibuprofen use.

Pharmacotherapeutic group: other cardiac preparations, ATC code: C01 EB16

Ibuprofen is a NSAID that possesses anti-inflammatory, analgesic and antipyretic activity. Ibuprofen is a racemic mixture of S(+) and R(-) enantiomers. In vivo and in vitro studies indicate that the S(+) isomer is responsible for the clinical activity. Ibuprofen is a non selective inhibitor of cyclo-oxygenase, leading to reduced synthesis of prostaglandins.

Since prostaglandins are involved in the persistence of the ductus arteriosus after birth, this effect is believed to be the main mechanism of action of ibuprofen in this indication.

In a dose-response study of Bifen in 40 preterm newborn infants, the ductus arteriosus closure rate associated to the 10-5-5 mg/kg dose regimen was 75% (6/8) in neonates of 27-29 weeks' gestation and 33% (2/6) in neonates of 24-26 weeks' gestation.

Prophylactic use of Bifen in the first 3 days of life (starting within 6 hours of birth) in preterm newborn infants less than 28 weeks of gestational age was associated with increased incidence of renal failure and pulmonary adverse events including hypoxia, pulmonary hypertension, pulmonary haemorrhage, as compared to curative use. Conversely, a lower incidence of neonatal grade III-IV intraventricular haemorrhage and of surgical ligation was associated with prophylactic use of Bifen.

Bifen is rapidly absorbed following administration and is rapidly distributed throughout the whole body. The excretion is rapid and complete via the kidneys.

Maximum plasma concentrations are reached 45 minutes after ingestion if taken on an empty stomach. When taken with food, peak levels are observed after 1 to 2 hours. These times may vary with different dosage forms.

The half life of Bifen is about 2 hours.

In limited studies, Bifen appears in the breast milk in very low concentrations.

Ibuprofen is rabidly absorbed following administration and is rapidly distributed throughout the whole body. The excretion is rapid and complete via the kidneys.

Maximum plasma concentrations are reached 45 minutes after ingestion if taken on an empty stomach. When taken with food, peak levels are observed after 1 to 2 hours. These times may vary with different dosage forms.

Elimination half-life is approximately 2 hours.

In limited studies, ibuprofen appears in the breast milk in very low concentrations.

The pharmacokinetic profile of Bifen compared with that of conventional-release 400mg tablets showed that the sustained-release formulation reduced the peaks and troughs characteristic of the conventional-release tablets and gave higher levels at 5, 10, 15 and 24 hours. Compared with conventional-release tablets, the area under the plasma concentration time curve for sustained-release tablets was almost identical.

Both mean plasma profiles and the pre-dose plasma levels showed no major differences between the young and elderly age groups. In several studies, Bifen produced a double peak plasma profile when taken under fasting conditions. The elimination half-life of ibuprofen is approximately 2 hours. Ibuprofen is metabolised in the liver to two inactive metabolites and these, together with unchanged ibuprofen, are excreted by the kidney either as such or as conjugates. Excretion by the kidney is both rapid and complete. Ibuprofen is extensively bound to plasma proteins.

Ibuprofen is a racemic mixture of [-]R- and [+]S-isomers. In vivo and in vitro studies indicate that the [+]S-isomer is responsible for clinical activity. The [-]R-form, while thought to be pharmacologically inactive, is slowly and incompletely (~60%) interconverted into the active [+]S species in adults. The [-]R-isomer serves as a circulating reservoir to maintain levels of active drug. The pharmacokinetic parameters of Bifen determined in a study with volunteers are presented below.

Table 4: Pharmacokinetic Parameters of Intravenous Ibuprofen

The pharmacokinetic parameters of Bifen determined in a study with febrile pediatric patients are presented in Table 5. It was observed that the median Tmax was at the end of the infusion and that Bifen had a shorter elimination half-life in pediatric patients compared to adults. The volume of distribution and clearance increased with age.

Table 5: Pharmacokinetic Parameters of 10 mg/kg Intravenous Ibuprofen, Pediatric Patients, by Age Group

Ibuprofen, like most NSAIDs, is highly protein bound ( > 99% bound at 20 mcg/mL). Protein binding is saturable, and at concentrations > 20 mcg/mL binding is nonlinear. Based on oral dosing data, there is an age- or fever-related change in volume of distribution for ibuprofen.

Distribution

Although a great variability is observed in the premature population, peak plasma concentrations are measured around 35-40 mg/l after the initial loading dose of 10 mg/kg as well as after the last maintenance dose, whatever gestational and postnatal age. Residual concentrations are around 10-15 mg/l 24 hours after the last dose of 5 mg/kg.

Plasma concentrations of the S-enantiomer are much higher than those of the R-enantiomer, which reflects a rapid chiral inversion of the R- to the S-form in a proportion similar to adults (about 60%).

The apparent volume of distribution is on average 200 ml/kg (62 to 350 according to various studies). The central volume of distribution may depend on the status of the ductus and decrease as the ductus closes.

In vitro studies suggest that, similarly to other NSAIDs, ibuprofen is highly bound to plasma albumin, although this seems to be significantly lower (95 %) compared with adult plasma (99 %). Ibuprofen competes with bilirubin for albumin binding in newborn infant serum and, as a consequence, the free fraction of bilirubin may be increased at high ibuprofen concentrations.

Elimination

Elimination rate is markedly lower than in older children and adults, with an elimination half-life estimated at approximately 30 hours (16-43). The clearance of both enantiomers increases with gestational age, at least in the range of 24 to 28 weeks.

PK-PD relationship

In preterm newborns ibuprofen significantly reduced plasma concentrations of prostaglandins and their metabolites, particularly PGE2 and 6-keto-PGF-1-alpha. Low levels were sustained up to 72 hours in neonates who received 3 doses of ibuprofen, whereas subsequent re-increases were observed at 72 hours after only 1 dose of ibuprofen.

None known.

Not applicable

None.

Bifen solution must not be in contact with any acidic solution such as certain antibiotics or diuretics. A rinse of the infusion line must be performed between each product administration.

Not applicable.

Not applicable

None.

As for all parenteral products, ampoules of Bifen should be visually inspected for particulate matter and the integrity of the container prior to use. Ampoules are intended for single use only, any unused portions must be discarded.

Chlorhexidine must not be used to disinfect the neck of the ampoule as it is not compatible with the Bifen solution. Therefore, for asepsis of the ampoule before use, ethanol 60% or isopropyl alcohol 70% is recommended.

When disinfecting the neck of the ampoule with an antiseptic, to avoid any interaction with the Bifen solution, the ampoule must be completely dry before it is opened.

The required volume to be given to the infant should be determined according to body weight, and should be injected intravenously as a short infusion over 15 minutes, preferably undiluted.

Use only sodium chloride 9 mg/ml (0.9%) solution for injection or glucose 50 mg/ml (5%) solution to adjust injection volume.

The total volume of solution injected to preterm infants should take into account the total daily fluid volume administered. A maximal volume of 80 ml/kg/day on the first day of life should usually be respected; this should be progressively increased in the following 1-2 weeks (about 20 ml/kg birthweight/day) up to a maximal volume of 180 ml/kg birthweight/day.

Before and after administration of Bifen, to avoid contact with any acidic solution, rinse the infusion line over 15 minutes with 1.5 to 2 ml of either sodium chloride 9 mg/ml (0.9%) or glucose 50 mg/ml (5%), solution for injection.

After first opening of an ampoule, any unused portions must be discarded.

Any unused product or waste material should be disposed of in accordance with local requirements.