Alendronic acid

Pharmacological properties

sodium alendronate belongs to the group of aminobisphosphonates. It is a synthetic analogue of natural pyrophosphate. inhibits the precipitation of calcium phosphate, blocks its transformation into hydroxyapatite, delays the aggregation of apatite crystals with the formation of larger crystals and accelerates their reverse dissolution. the selective effect is due to the high affinity of bisphosphonates to the mineral components of bones. acts as an effective non-hormonal specific inhibitor of osteoclast-mediated bone resorption. the exact mechanisms of this process are not fully understood. restores a positive balance between resorption and bone restoration. increases the mineral density of the bones of the spine, pelvis, etc., promotes the formation of bone tissue with a normal histological structure. prevents the appearance of new bone fractures. reduces plasma calcium levels due to inhibition of bone resorption and reduction of calcium release from bone tissue. the calcium-lowering effect of the drug, mediated by the suppression of osteoclasts, is observed after 1-2 days.

Pharmacokinetics Sodium alendronate is absorbed in the digestive tract by 25%. The absolute bioavailability of tablets (5 to 10 mg) taken on an empty stomach 2 hours before meals is 0.64% (for women) and 0.59% (for men). Bioavailability decreases (by about 40%) when taking alendronate half an hour to an hour before a regular breakfast. The bioavailability of alendronate is negligible when taken with food or within 2 hours after eating. The concomitant use of alendronate with other drinks (including mineral water, coffee, orange juice) reduces its bioavailability by 60%. Studies conducted in laboratory rats showed that with iv administration at a dose of 1 mg / kg, alendronate is temporarily distributed in the soft tissues, but then quickly redistributed. Half of the absorbed dose is excreted mainly by the kidneys unchanged for 72 hours, and the rest accumulates in the bone tissue for a long time, is eliminated very slowly due to the connection with bone tissue. T_½ bone alendronate is several years old.

Approximately 78% of alendronate binds to plasma proteins and is not metabolized. The concentration of the drug in blood plasma is negligible (5 ng / ml) and decreases by 95% within 6 hours after infusion.

After a single injection of 10 mg of alendronate, its renal clearance was 71 ml / min, and the systemic clearance did not exceed 200 ml / min.

Indications

Treatment of postmenopausal osteoporosis. the drug reduces the risk of vertebral and femoral fractures.

Application

Recommended dose: 1 tablet 70 mg once a week.

The duration of treatment is determined by the doctor.

The tablet must be taken with water at least 30 minutes before the first days intake of food, drinks or other medicines. Other drinks (including mineral water), food, and certain drugs can help reduce the absorption of alendronate.

To facilitate the entry of the drug into the stomach and thus reduce its irritating effect on the mucous membrane of the oral cavity, pharynx and esophagus:

• it is necessary to take the drug with a glass of water (at least 200 ml) in the morning after waking up;
• do not chew the tablet - the possibility of developing ulcers of the oral cavity and pharynx;
• the first daily meal - only 30 minutes after taking the pill;
• after taking the drug, patients should not lie for at least 30 minutes;
• the drug should not be taken before bedtime or before morning rise from bed.

The interval between taking alendronate and other drugs taken orally should be at least 1 hour.

Additionally, it is necessary to take calcium and vitamin D if the intake of these substances with food is not enough.

You should take the drug on the same day of the week.If you accidentally skip, you need to take 1 tablet the next morning. Then continue taking as usual - use the next pill on the day that was chosen from the very beginning of treatment.

Use in elderly patients. There is no need to adjust the dose in the elderly.

Renal failure. For patients whose creatinine clearance is 35 ml / min, there is no need to adjust the dose.

The effect of the drug in the treatment of osteoporosis caused by corticosteroids has not been investigated.

Contraindications

• Hypersensitivity to sodium alendronate or any other component of the drug; pathology of the esophagus (stricture or achalasia), which cause a delay in the evacuation of the contents of the esophagus; inability to stand or sit upright for 30 minutes after taking the drug; hypocalcemia; severe renal failure (creatinine clearance 35 ml / min).

Side effects

From the nervous system: headache, dizziness, taste disturbance (bitter or unusual taste in the mouth after taking the drug).

From the side of the organ of vision: uveitis, scleritis, episiscleritis.

From the gastrointestinal tract: abdominal pain, dyspepsia, constipation, diarrhea, flatulence, ulcers of the oral cavity, pharynx and esophagus, dysphagia, tension of the abdominal wall, heartburn, regurgitation of gastric contents, nausea, vomiting, gastritis, esophagitis, esophageal erosion, esophageal stricture , perforation, ulcer, bleeding of the gastrointestinal tract (including the oral cavity, pharynx, esophagus, stomach), melena.

On the part of the skin and subcutaneous tissue: rash, urticaria, itching, erythema (redness), rash, aggravated by the influence of light, isolated cases of severe skin reactions, including Stevens-Johnson syndrome and toxic epidermal necrolysis, hair loss (alopecia).

From the musculoskeletal system and connective tissue: pain in the bones, muscles or joints, osteonecrosis, fractures of the femur, swelling of the joints.

From the side of metabolism, metabolism: symptomatic hypocalcemia, often due to the presence of provoking factors.

General disorders: transient symptoms (muscle pain, malaise and, in rare cases, fever), which usually occur at the beginning of treatment, asthenia, peripheral edema.

From the immune system: allergic reactions, including angioedema.

Laboratory analysis data: hypocalcemia, hypophosphatemia (in the treatment of alendronate 10 mg / kg / day).

special instructions

The drug can cause local irritation of the mucous membrane of the upper gastrointestinal tract. since there is a risk of exacerbation of the underlying disease, it is necessary to prescribe the drug with caution to patients with dysphagia, diseases of the esophagus, gastritis, duodenitis, peptic ulcer, as well as patients who have suffered from severe gastrointestinal tract diseases (gastric ulcer, acute gastrointestinal bleeding, surgical interventions in the upper gastrointestinal tract, with the exception of pyloroplasty).

In patients with Barretts esophagus, the drug should be prescribed individually, provided that the expected benefits prevail over the risk.

Since taking the medicine can cause esophagitis (inflammation of the esophagus), ulcer or erosion of the esophagus, which in exceptional cases may be complicated by the appearance of esophageal stricture, it is necessary to carefully monitor the occurrence of any manifestations of such an effect. If symptoms such as dysphagia, pain when swallowing, pain in the sternum, heartburn (occurrence or intensification of manifestations of existing heartburn) occur, the drug should be discontinued and consult a doctor.

Patients with risk factors for jaw osteonecrosis (such as cancer, chemotherapy, radiation therapy, corticosteroids, inappropriate oral hygiene, smoking, periodontal disease, osteoporosis) should undergo an oral examination with appropriate preventive dental care before starting treatment with bisphosphonates. During therapy, such patients should avoid invasive dental procedures whenever possible.In patients who develop jaw osteonecrosis during treatment with bisphosphonates, dental surgery can only worsen the condition. Regarding patients who require dental intervention, there is no additional data or information that the abolition of bisphosphonates could reduce the risk of osteonecrosis of the jaw.

Before starting therapy with Alendra, it is necessary to correct hypocalcemia. Other mineral metabolism disorders (such as vitamin D deficiency and hypothyroidism / hypothyroidism) should also be effectively treated. In patients with such conditions during therapy, it is necessary to monitor the level of calcium in the blood plasma and the symptoms of hypocalcemia.

Due to the possible effect of alendronate with respect to increasing bone mineralization, a decrease in the level of calcium in plasma and phosphates may occur, especially in patients taking GCS, in which calcium absorption may decrease. It is usually mild and asymptomatic. However, asymptomatic hypocalcemia is reported, which sometimes had a severe form and often occurred in patients with a predisposition to it (for example, hypothyroidism, vitamin D deficiency and malabsorption / malabsorption of calcium). Therefore, ensuring adequate intake of calcium and vitamin D is especially important for patients taking GCS.

In connection with possible bilateral fractures of the proximal femur with prolonged use of the drug (more than 18 months), if they occur, it is necessary to examine the contralateral femur. Also, due to the possible poor coalescence of such fractures, it is recommended that therapy with bisphosphonates be discontinued until the patient is examined and continued, depending on the assessment of the risk / benefit ratio for the patient.

This drug is not indicated for patients with rare hereditary diseases such as galactose intolerance, Lapp lactase deficiency or glucose-galactose malabsorption.

Use during pregnancy or lactation. The drug is not prescribed during pregnancy and lactation.

Children. Do not use in children under the age of 18 years.

The ability to influence the reaction rate when driving vehicles or other mechanisms. There was no effect on the ability to drive vehicles and mechanisms. However, certain adverse reactions reported with the use of the drug may affect the ability of some patients to drive vehicles or mechanisms.

Interactions

Absorption of alendronate sodium may be impaired if it is taken simultaneously with calcium preparations (including nutritional supplements) and antacids. the interval between taking the drug and other drugs that are taken orally should be at least 1 hour.

The combined use of sodium alendronate and hormone replacement therapy (estrogens + progesterones) led to a greater increase in bone mass and a more significant decrease in bone resorption compared to a separate application of the first and second methods of treatment.

NSAIDs enhance the gastrotoxic effect of sodium alendronate.

With the simultaneous use of sodium alendronate with corticosteroids, hypocalcemia may be enhanced, since corticosteroids inhibit the activity of vitamin D, which leads to a decrease in calcium absorption and its more active elimination.

Caution is advised when prescribing alendronate with aminoglycosides, which reduce plasma calcium levels for a long time.

In the treatment of malignant hypercalcemia, the use of thiazides, which reduce the loss of calcium in the urine, can weaken the calcium-lowering effect of sodium alendronate.

No other drug interactions that have clinical significance have been observed.

Overdose

Symptoms: hypocalcemia, hypophosphatemia, upset stomach function, heartburn, esophagitis, gastritis, or gastric ulcer.

Treatment: to bind alendronate, you need to drink milk or take antacids. Due to the risk of irritation of the esophagus, vomiting should not be induced; the patient should also maintain an upright position.

Storage conditions

At a temperature not exceeding 25 ° C in the original packaging.