Digoxin... Dailtiazem hydrochloride..... Dobutamine hydrochloride..... Dobutamine hydrochloride...Doxycyclin ...Enalapril " Convertin

**********************************************

5.      Digoxin :

    Trade name: Lanoxicaps, Lanoxin, Novo-Digoxin (CAN)    

Drug classes:   

• Cardiac glycoside
• Cardiotonic agent

Pregnancy: (Category C)

Therapeutic actions

Increases intracellular calcium and allows more calcium to enter the myocardial cell during depolarization via a sodium---potassium pump mechanism; this increases force of contraction (positive inotropic effect), increases renal perfusion (seen as diuretic effect in patients with CHF), decreases heart rate (negative chronotropic effect), and decreases AV node conduction velocity. 

Indications

·         CHF

·         Atrial fibrillation

·         Atrial flutter

·         Paroxysmal atrial tachycardia

Dose 

by mouth, rapid digitalization, 1–1.5 mg in divided doses over 24 hours; less urgent digitalization, 250–500 micrograms daily (higher dose may be divided),  Maintenance, 62.5–500 micrograms daily (higher dose may be divided) according to renal function and, in atrial fibrillation, on heart-rate response; usual range, 125–250 micrograms daily (lower dose may be appropriate in elderly)
 Emergency loading dose by intravenous infusion, 0.75–1 mg over at least 2 hours  then maintenance dose by mouth on the following day

Contraindications:

• Contraindications: allergy to digitalis preparations, ventricular tachycardia, ventricular fibrillation, heart block, sick sinus syndrome, IHSS, acute MI, renal insufficiency and electrolyte abnormalities (decreased K⁺, decreased Mg⁺⁺, increased Ca⁺⁺).
• Use cautiously with pregnancy and lactation.

Side effects:

• CNS: Headache, weakness, drowsiness, visual disturbances
• GI: GI upset, anorexia
• CV: Arrhythmias

Nursing Considerations

• Monitor apical pulse for 1 min before administering; hold dose if pulse <60 in adult or <90 in infant, retake pulse in 1 h. If adult pulse remains <60 or infant <90, hold drug and notify prescriber. Note any change from baseline rhythm or rate.
• Check dosage and preparation carefully.
• Avoid IM injections, which may be very painful.
• Follow diluting instructions carefully, and use diluted solution promptly.
• Avoid giving with meals; this will delay absorption.
• Have emergency equipment ready; have K+ salts, lidocaine, phenytoin, atropine, and cardiac monitor on standby in case toxicity develops.
• Monitor for therapeutic drug levels: 0.5---2 ng/mL.

*********************************************************

6.      Dailtiazem hydrochloride :

             Trade name: Alti-Diltiazem ,Apo-Diltiaz, Cardizem, Dilacor XR, 

                 Gen-Diltiazem  , Novo-Diltazem  , Nu-Diltiaz , Tiamate, Tiazac

             Drug classes

·         Calcium channel-blocker

·         Antianginal agent

·         Antihypertensive

Pregnancy: (Category C)

     Action: Calcium-channel blockers "anti anginal, antihypertensive"

Inhibits the movement of calcium ions across the membranes of cardiac and arterial muscle cells, resulting in the depression of impulse formation in specialized cardiac pacemaker cells, slowing of the velocity of conduction of the cardiac impulse, depression of myocardial contractility, and dilation of coronary arteries and arterioles and peripheral arterioles; these effects lead to decreased cardiac work, decreased cardiac energy consumption, and in patients with vasospastic (Prinzmetal's) angina, increased delivery of oxygen to myocardial cells.

Indications

·         Angina pectoris due to coronary artery spasm (Prinzmetal's variant angina)

·         Effort-associated angina; chronic stable angina in patients not controlled by β-adrenergic blockers, nitrates

·         Essential hypertension (sustained release)

·         Treatment of hypertension (sustained release, Tiamate)

·         Paroxysmal supraventricular tachycardia (parenteral)

Dose

Available Forms: Tablets--30, 60, 90, 120 mg; SR capsules--60, 90, 120, 180, 240, 300 mg; injection--25, 50 mg as 5 mg/mL
Evaluate patient carefully to determine the appropriate dose of this drug.

  Angina, 60 mg 3 times daily (elderly initially twice daily);                     increased if necessary to 360 mg daily 

Pediatric: Safety and efficacy not established.

 Contraindications/cautions

       Allergy to diltiazem,

        impaired hepatic or renal function,

        sick sinus syndrome, hypotension,

       pulmonary congestion, and MI

        heart block (second or third degree), and

        lactation

Side effects

·         CNS: Dizziness, light-headedness, headache, asthenia, fatigue

·         GI: Nausea, hepatic injury

·         CV: Peripheral edema, hypotension, arrhythmias, bradycardia, AV block, asystole

·         Dermatologic: Flushing, rash

Clinically important interactions

• Drug-drug
• Increased serum levels and toxicity of cyclosporine if taken concurrently with diltiazem

Nursing Considerations

• Monitor patient carefully (BP, cardiac rhythm, and output) while drug is being titrated to therapeutic dose; dosage may be increased more rapidly in hospitalized patients under close supervision.
• Monitor BP carefully if patient is on concurrent doses of nitrates.
• Monitor cardiac rhythm regularly during stabilization of dosage and periodically during long-term therapy.
• Report irregular heart beat, shortness of breath, swelling of the hands or feet, pronounced dizziness, constipation.

********************************************************************************

7.      Dobutamine hydrochloride:

        Trade name:   Dobutrex

        Drug classes:

·         Sympathomimetic

·         β₁-selective adrenergic agonist

       Pregnancy: (Category B)

Therapeutic actions:

Positive inotropic effects are mediated by β₁- adrenergic receptors in the heart; increases the force of myocardial contraction with relatively minor effects on heart rate, arrhythmogenesis; has minor effects on blood vessels.

         Indications

·         For inotropic support in the short-term treatment of adults with cardiac decompensation due to depressed contractility, resulting from either organic heart disease or from cardiac surgical procedures

·         Investigational use in children with congenital heart disease undergoing diagnostic cardiac catheterization, to augment CV function

         Dosage

§  Available Forms: Injection 12.5 mg/mL.

§  Administer only by IV infusion.

§  Titrate on the basis of the patient's homodynamic/renal response.

§  Close monitoring is necessary.

          Adult:

2.5---15 µg/kg/min IV is usual rate to increase cardiac output; rarely, rates up to 40 µg/kg per minute are needed.  

IV facts

• Preparation: Reconstitute by adding 10 mL Sterile Water for Injection or 5% Dextrose Injection to 250-mg vial. If material is not completely dissolved, add 10 mL of diluent. Further dilute to at least 50 mL with 5% Dextrose Injection, 0.9% Sodium Chloride Injection, or Sodium Lactate Injection. Store reconstituted solution under refrigeration for 48 h or at room temperature for 6 h. Store final diluted solution in glass or via flex container at room temperature. Stable for 24 h. Do not freeze. (Note: drug solutions may exhibit a color that increases with time; this indicates oxidation of the drug, not a loss of potency.)
• Infusion: May be administered through common IV tubing with dopamine, lidocaine, tobramycin, nitroprusside, potassium chloride, or protamine sulfate. Titrate rate based on patient response--P, BP, rhythm; use of an infusion pump is suggested.
• Incompatibilities: Do not mix drug with alkaline solutions, such as 5% Sodium Bicarbonate Injection; do not mix with hydrocortisone sodium succinate, cefazolin, cefamandole, neutral cephalothin, penicillin, sodium ethacrynate; sodium heparin.
• Y-site Incompatibilities: Do not mix with acyclovir, alteplase, aminophylline, foscarnet.

Adverse effects

• CNS: Headache
• GI: Nausea
• CV: Increase in heart rate, increase in systolic blood pressure, increase in ventricular ectopic beats (PVCs), anginal pain, palpitations, shortness of breath

Clinically important interactions

• Drug-drug

v  Increased effects with TCAs (eg, imipramine), furazolidone, methyldopa

v  Risk of severe hypertension with β-blockers

v  Decreased effects of guanethidine with dobutamine

Nursing Considerations

v  Arrange to digitalize patients who have atrial fibrillation with a rapid ventricular rate before giving dobutamine--dobutamine facilitates AV conduction.

v  Monitor urine flow, cardiac output, pulmonary wedge pressure, ECG, and BP closely during infusion; adjust dose/rate accordingly.

********************************************************

8.      Dopamine Hydrochloride:

Trade names: Intropin, docard

Class: Direct & indirect acting adrenergic agent.

N.B.: Available for hospital use only on 5 ml ampoules containing 200 mg Doparninc hydrochloride.

Pregnancy: (Category C)

Action:

      It is the immediate precursor of epinephrine in the body.

      It produces direct stimulation of β1 receptors resulting in increasing myocardial contraction,   cardiac output as well as increase renal blood flow & sodium excretion.

      It exerts little effect on diastolic B.P. & induce fewer arrhythrrias that seen on other adrenergic.

      Alpha receptors, which are stimulated by higher doses of dopamine exerts vasodilatation effects which can override the vasodilating effect.

      In higher doses it stimulates alpha receptors leading to peripheral vasoconstriction.

Indications:

§  Cardiogenic shocks especially in M.I. associated with sever C.H.F

§  Hypotension due to poor cardiac out put.

§  Shock associated with septicemia, trauma, heart surgery, renal failure & C.H.F.

§  Cardiomyopathy.

§  In lower doses (1-5 Mcg/kg/min) used in renal failure.

Contraindications:

§  Pheochromocytoma, uncorrected tachycardia, arrhythmias.

§  Hypovolemia.

§  Safety and efficacy is not established in children.

Side effects:

§  GI: Nausea and vomiting.

§  CV: Ectopic heart-beats, tachycardia or bradycardia, anginal pain, palpitation, hypotension or hypertension, dyspnea, wide QRS complex.

§  Others: headache.

Dosage and administration:

N.B.: This is a potent drug.

 It must be diluted before administration to the patient.

Suggested dilution:

Transfer contents of one ampoule (5ml containing 200 mg of dopamine) by aseptic technique to either 250 or 500 ml bottle of sterile I.V. solution (saline, dextrose 5% or ringer lactate). These dilutions will yield a final concentration for administration as follows.

-          250 ml dilution contains 800 mcg\ml of dopamine.

-          500 ml dilution contains 400 mcg\ml of dopamine.

N.B.:

1-      Solution stable after dilution for 24 hours.

2-      Don’t add dopamine to NaHCO3 or other alkaline I.V. solutions since the drug is inactivated in alkaline solution.

Rate of administration.

Through a suitable I.V. needle or a catheter & through an electronic infusion pump, rate is regulated according to required dose.

Dose:

Renal dose: 1-5 Mcg\kg\minute.

Cardiac dose: start initially of 5 Mcg/kg/min then increase by increments up to a rate of 20-50 Mcg/kg/min.

Nursing considerations:

§  Administer only by IV INFUSION (Not IV bolus nor IM)

§  Drug must be diluted before use.

§  Administer drug through a central line or a big vein (vein in the anticupital fossa is preferred over those in the hand).

§  Stop the drug by small increments.

§  Solution is stable for 24 hrs, protect it from light.

§  Monitor B.P. & ECG continuously during drug administration.

§  Monitor intake & out put.

§  Monitor patient for occurrence of side effects.

§  Check I.V. site for sighs of extravasations.

§  Drug should be administered through electronic infusion device.

********************************************************

9.      Doxycyclin :

           Trade names: Doxylin, Doxypal, Doxypharm, Doxacylin. Apo-

                                   Doxy, Doryx, Doxy-Caps, Doxycin 

                                   Doxychel Hyclate, Doxytec, Novo-Doxylin , Nu-

                                   Doxycycline ,Vibra-Tabs, Vibramycin

 Class: Antibiotic, tetracycline.

Pregnancy: (Category D)

   Therapeutic actions

Bacteriostatic: inhibits protein synthesis of susceptible bacteria, causing cell death

  Indications

• Infections caused by rickettsiae; M. pneumoniae; agents of psittacosis, ornithosis, lymphogranuloma venereum and granuloma inguinale; B. recurrentis; H. ducreyi; P. pestis; P. tularensis; B. bacilliformis; Bacteroides; V. comma; V. fetus; Brucella; E. coli; E. aerogenes; Shigella; A. calcoaceticus; H. influenza; Klebsiella; D. pneumoniae; S. aureus
• When penicillin is contraindicated, infections caused by N. gonorrhoeae, T. pallidum, T. pertenue, L. monocytogenes, Clostridium, B. anthracis; adjunct to amebicides in acute intestinal amebiasis
• Oral tetracyclines used for acne, uncomplicated adult urethral, endocervical or rectal infections caused by C. trachomatis
• Unlabeled use: prevention of "traveler's diarrhea" commonly caused by enterotoxigenic E. coli

Contraindications/cautions

v  Allergy to tetracyclines,

v  renal or hepatic dysfunction,

v  pregnancy, and

v   Lactation.

Dosage form:

Available Forms: Tablets--100 mg; powder for oral suspension--25 mg; syrup--50 mg; powder for injection--100, 200 mg

         Dose: 

§  200 mg on first day, then 100 mg daily; severe infections (including refractory urinary-tract infections), 200 mg daily

§   Early syphilis, 100 mg twice daily for 14 days; late latent syphilis 200 mg twice daily for 28 days

§   Uncomplicated genital Chlamydia, non-gonococcal urethritis, 100 mg twice daily for 7 days (14 days in pelvic inflammatory disease

§   Anthrax (treatment or post-exposure prophylaxis 100 mg twice daily;

§   Child (only if alternative antibacterial cannot be given) [unlicensed dose] 5 mg/kg daily in 2 divided doses (max. 200 mg daily)

§  Geriatric or Renal Failure Patients:

IV doses of doxycycline are not as toxic as other tetracyclines in these patients.

Adverse effects

• GI: Fatty liver, liver failure, anorexia, nausea, vomiting, diarrhea, glossitis, dysphagia, enterocolitis, esophageal ulcer
• Hematologic: Hemolytic anemia, thrombocytopenia, neutropenia, eosinophilia, leukocytosis, leukopenia
• Dermatologic: Phototoxic reactions, rash, exfoliative dermatitis (more frequent and more severe with this tetracycline than with any others)
• Dental: Discoloring and inadequate calcification of primary teeth of fetus if used by pregnant women, discoloring and inadequate calcification of permanent teeth if used during period of dental development
• Local: Local irritation at injection site
• Other: Super infections, nephrogenic diabetes insipidus syndrome

Clinically important interactions

• Drug-drug

·         Decreased absorption with antacids, iron, alkali

·         Decreased therapeutic effects with barbiturates, carbamazepine, phenytoins

·         Increased digoxin toxicity with doxycycline

·         Increased nephrotoxicity with methoxyflurane

·         Decreased activity of penicillins

• Drug-food

·         Decreased effectiveness of doxycycline if taken with food, dairy products

• Drug-lab test

·         Interference with culture studies for several days following therapy

Nursing consideration:

·         Administer the oral medication without regard to food or meals; if GI upset occurs, give with meals.

·         Do not give with antacid, milk, or any product that contains Calcium, Zink, aluminum, magnesium, and ferrous salts, because these products decrease the absorption of the drug.

·         Protect patient from light and sun exposure.

·         Report rash, itching; difficulty breathing; dark urine or light-colored stools; pain at injection site

************************************************************

10.  Enalapril " Convertin ' :

                  Trade names:        Enalaprilat, Convertin

                  Drug classes

·         Antihypertensive

·         ACE inhibitor

Pregnancy: (Category C/ D if used in the 2nd or 3rd trimesters.]

Therapeutic actions

Renin, synthesized by the kidneys, is released into the circulation where it acts on a plasma precursor to produce angiotensin I, which is converted by angiotensin-converting enzyme to angiotensin II, a potent vasoconstrictor that also causes release of aldosterone from the adrenals; both of these actions increase BP. Enalapril blocks the conversion of angiotensin I to angiotensin II, decreasing BP, decreasing aldosterone secretion, slightly increasing serum K⁺ levels, and causing Na⁺ and fluid loss; increased prostaglandin synthesis also may be involved in the antihypertensive action.

Indications

• Treatment of hypertension alone or in combination with thiazide-type diuretics
• Treatment of acute and chronic CHF
• Treatment of asymptomatic left ventricular dysfunction (LVD)
• Treatment of acute hypertension--IV

Contraindications/cautions

• Contraindication: allergy to enalapril.
• Use cautiously with impaired renal function; salt/volume depletion--hypotension may occur; lactation

 Dose

§  Hypertension, used alone, initially 5 mg once daily;

§  if used in addition to diuretic, in elderly patients, or in renal impairment, initially 2.5 mg daily;

§   Usual maintenance dose 10–20 mg once daily;

§  In severe hypertension may be increased to max. 40 mg once daily

§  Heart failure (adjunct), asymptomatic left ventricular dysfunction, initially 2.5 mg daily under close medical supervision; usual maintenance dose 20 mg daily in 1–2 divided doses

  Adverse effects

• CNS: Headache, dizziness, fatigue, insomnia, paresthesias
• GI: Gastric irritation, nausea, vomiting, diarrhea, abdominal pain, dyspepsia, elevated liver enzymes
• CV: Syncope, chest pain, palpitations, hypotension in salt/volume depleted patients
• Hematologic: Decreased hematocrit and hemoglobin
• GU: Proteinuria, renal insufficiency, renal failure, polyuria, oliguria, urinary frequency, impotence
• Other: Cough, muscle cramps, hyperhidrosis

    Clinically important interactions

• Drug-drug
• Decreased hypotensive effect if taken concurrently with indomethacin, rifampin

         Nursing Considerations

•  If pt undergoes any types of surgery alert surgeon and mark patient's chart with notice that enalapril is being taken; the angiotensin II formation subsequent to compensatory renin release during surgery will be blocked; hypotension may be reversed with volume expansion.
• Monitor patients on diuretic therapy for excessive hypotension following the first few doses of enalapril.
• Monitor patient closely in any situation that may lead to a fall in BP secondary to reduced fluid volume (excessive perspiration and dehydration, vomiting, diarrhea) because excessive hypotension may occur.
• Arrange for reduced dosage in patients with impaired renal function.
• Monitor patient carefully because peak effect may not be seen for 4 h. Do not administer second dose until checking BP.

***********************************************************