Citalopram

By Y. Uruk. Notre Dame College of Ohio.

Many automated ECG machines can give a preliminary interpretation of a tracing; however cheap 40 mg citalopram otc treatment 2015, all automated in- terpretations require analysis and sign-off by a physician order citalopram 20mg visa treatment 8th february. If the QRS is upright (more positive than negative) in leads I and aVF, the axis is normal. The QT inter- val usually does not exceed one half of the RR interval (the distance between two R waves). Count the number of QRS cycles in a 6-s strip and multiply it by 10 to roughly estimate the rate. If the rhythm is regular you can be more exact in determining the rate by dividing 300 by the number of 0. Determine whether each QRS is preceded by a P wave, look for variation in the PR interval and RR interval (the duration between two QRS cycles), and look for ectopic beats. One way to determine LVH is to calculate the sum of the S wave in 19 V1 or V2 plus the R wave in V5 or V6. Check for the presence of ST-segment elevation or depres- sion, Q waves, inverted T waves, and poor R-wave progression in the precordial leads. A more detailed discussion of each of these categories is presented in the following sections. BASIC INFORMATION Equipment Bipolar Leads • Lead I: Left arm to right arm • Lead II: Left leg to right arm • Lead III: Left leg to left arm Precordial Leads: V1 to V6 across the chest, as shown in the section on electrocardio- grams in Chapter 13 (see Figure 13–9, page 267). With normal sinus rhythm, the P wave is upright in leads I, II, aVF, V4, V5, and V6 and inverted in aVR. The first negative deflection of the QRS complex (not always present and, if present, may be pathologic) • R Wave. The first positive deflection (R) is the positive deflection that sometimes occurs after the S wave) • S Wave. Normally upright in leads I, II, V, V, V, and V and inverted in aVR 19 3 4 5 6 AXIS DEVIATION The term axis, which represents the sum of the vectors of the electrical depolarization of the ventricles, gives some idea of the electrical orientation of the heart in the body. In a healthy person, the axis is downward and to the left, as shown in Figure 19–3. The QRS axis is midway between two leads that have QRS complexes of equal ampli- tude, or the axis is 90 degrees to the lead in which the QRS is isoelectric, that is, the ampli- tude of the R wave equals the amplitude of the S wave. QRS negative in I and positive in aVF, +105 to +180 degrees • Extreme Right Axis Deviation. QRS negative in I and negative in aVF, +180 to 19 +270 or –90 to –180 degrees Clinical Correlations • RAD. Seen with RVH, RBBB, COPD, and acute PE (a sudden change in axis toward the right), as well as in healthy individuals (occasionally) • LAD. Seen with LVH, LAHB (–45 to –90 degrees), LBBB, and in some healthy in- dividuals 19 Basic ECG Reading 371 HEART RATE Bradycardia: Heart rate <60 bpm Tachycardia: Heart rate >100 bpm Rate Determination: Figure 19–4. RHYTHM Sinus Rhythms Normal: Each QRS preceded by a P wave (which is positive in II and negative in aVR) with a regular PR and RR interval and a rate between 60 and 100 bpm (Figure 19–5) Sinus Tachycardia: Normal sinus rhythm with a heart rate >100 bpm and <180 bpm (Figure 19–6) Clinical Correlations. Anxiety, exertion, pain, fever, hypoxia, hypotension, increased sympathetic tone (secondary to drugs with adrenergic effects [eg, epinephrine]), anticholin- ergic effect (eg, atropine), PE, COPD, AMI, CHF, hyperthyroidism, and others Sinus Bradycardia: Normal sinus rhythm with a heart rate <60 bpm (Figure 19–7) Clinical Correlations. Well-trained athlete, normal variant, secondary to medications (eg, beta-blockers, digitalis, clonidine), hypothyroidism, hypothermia, sick sinus syndrome (tachy–brady syndrome), and others 19 FIGURE 19–4 Sample strip for rapid rate determination (see text for procedure). Estimating the rate by counting the number of beats (eight) in the two 3-s intervals. Because the beats are separated by exactly four beats, you do not need to extrapolate. Treatment • If asymptomatic (good urine output, adequate BP, and normal sensorium), no ther- apy needed. Atrial Arrhythmias PAC: Ectopic atrial focus firing prematurely followed by a normal QRS (Figure 19–8). The compensatory pause following the PAC is partial; the RR interval between beats 4 and 6 is less than between beats 1 and 3 or 6 and 8. Usually not of clinical significance; can be caused by stress, caf- feine, and myocardial disease PAT: A run of three or more consecutive PACs.

In addition purchase 20 mg citalopram amex symptoms zithromax, a drug may also cause The above forms of hypersensitivity unwanted effects that can be grouped must be distinguished from allergies in- into minor or “side” effects and major or volving the immune system (p order citalopram 10mg with amex treatment questionnaire. Despite ap- rise to complaints or illness, or may propriate dosing and normal sensitivity, even cause death. For in- a higher dose than is required for the stance, the anticholinergic, atropine, is principal effect; this directly or indirect- bound only to acetylcholine receptors of ly affects other body functions. In excessive doses, it leptic, is able to interact with several inhibits the respiratory center and different receptor types. The dose de- is neither organ-specific nor receptor- pendence of both effects can be graphed specific. The distance between both DRCs tivity can often be avoided if the drug indicates the difference between the does not require the blood route to therapeutic and toxic doses. This margin reach the target organ, but is, instead, of safety indicates the risk of toxicity applied locally, as in the administration when standard doses are exceeded. This holds true for both With every drug use, unwanted ef- medicines and environmental poisons. In order to prescribing a drug, the physician should assess the risk of toxicity, knowledge is therefore assess the risk: benefit ratio. If certain body functions develop hyperreactivity, unwanted effects can occur even at nor- mal dose levels. Increased sensitivity of the respiratory center to morphine is found in patients with chronic lung dis- ease, in neonates, or during concurrent exposure to other respiratory depress- ant agents. The DRC is shifted to the left and a smaller dose of morphine is suffi- cient to paralyze respiration. Adverse Drug Effects 71 Decrease in Effect Respiratory depression pain perception Decrease in (nociception) Nociception Respira- Morphine tory overdose Safety activity Morphine margin Dose A. Adverse drug effect: overdosing Increased Effect sensitivity of respiratory Safety center margin Normal dose Dose B. Adverse drug effect: lacking selectivity Lüllmann, Color Atlas of Pharmacology © 2000 Thieme All rights reserved. These complexes mediate the activation The immune system normally functions of complement, a family of proteins that to rid the organism of invading foreign circulate in the blood in an inactive particles, such as bacteria. Immune re- form, but can be activated in a cascade- sponses can occur without appropriate like succession by an appropriate stimu- cause or with exaggerated intensity and lus. Activation as effective antigens or immunogens, of complement on blood cells results in capable by themselves of initiating an their destruction, evidenced by hemo- immune response. Most drugs or their lytic anemia, agranulocytosis, and metabolites (so-called haptens) must thrombocytopenia. During initial con- and an inflammatory reaction is trig- tact with the drug, the immune system gered. Attracted neutrophils, in a futile is sensitized: antigen-specific lympho- attempt to phagocytose the complexes, cytes of the T-type and B-type (antibody liberate lysosomal enzymes that dam- formation) proliferate in lymphatic tis- age the vascular walls (inflammation, sue and some of them remain as so- vasculitis). Usually, these pro- ver, exanthema, swelling of lymph cesses remain clinically silent. During nodes, arthritis, nephritis, and neuropa- the second contact, antibodies are al- thy. A detectable immune re- neously applied drug is bound to the sponse, the allergic reaction, occurs. Four types of lease signal molecules (lymphokines) reactions can be distinguished: into their vicinity that activate macro- Type 1, anaphylactic reaction. Binding of the drug provides the stimulus for the release of histamine and other media- tors. In the most severe form, a life- threatening anaphylactic shock devel- ops, accompanied by hypotension, bronchospasm (asthma attack), laryn- geal edema, urticaria, stimulation of gut musculature, and spontaneous bowel movements (p. Drug- antibody (IgG) complexes adhere to the surface of blood cells, where either circu- lating drug molecules or complexes al- Lüllmann, Color Atlas of Pharmacology © 2000 Thieme All rights reserved. Adverse Drug Effects 73 Reaction of immune system to first drug exposure Production of antibodies Drug (Immunoglobulins) (= hapten) Immune system e. Adverse drug effect: allergic reaction Lüllmann, Color Atlas of Pharmacology © 2000 Thieme All rights reserved. Drugs taken by the mother can be Drugs with established human ter- passed on transplacentally or via breast atogenicity include derivatives of vita- milk and adversely affect the unborn or min A (etretinate, isotretinoin [used the neonate.